"uuid","repository link","title","author","contributor","publication year","abstract","subject topic","language","publication type","publisher","isbn","issn","patent","patent status","bibliographic note","access restriction","embargo date","faculty","department","research group","programme","project","coordinates"
"uuid:1231eda8-ebde-43b7-abc6-bf8e6ba1d52e","http://resolver.tudelft.nl/uuid:1231eda8-ebde-43b7-abc6-bf8e6ba1d52e","An estimator for the Coulomb repulsion parameter U to generate vacuum referred binding energy schemes for lanthanides in compounds","Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2024","The U-value defined as the energy difference between the Eu4+/3+ and Eu3+/2+ charge transition levels (CTLs) is the most important parameter in constructing vacuum referred binding energy diagrams (VRBEs) with all the lanthanide CTLs with respect to the vacuum level of energy. The parameter is difficult to determine from experiment and the aim of this work is to establish a method to estimate the U-value from the average electronegativity of the cations in the compound. Since the U-value is controlled by the same physical processes, i.e., covalence and anion polarizability, as the centroid shift ϵc of the Ce3+ 5d configuration, one may estimate the U-value from that centroid shift. That method provides already good values for U for about 175 different compounds. Those U-values are compared with the average cation electronegativity χav, and relations will be established from which the U-value can be estimated with about ±0.1 eV accuracy from just the composition of the compound. It can be applied to all types of stoichiometric inorganic compounds like the halides (F, Cl, Br, I), chalcogenides (O, S, Se), and nitrides (N). The U-value complemented with the bandgap and the energy needed for electron transfer from the valence band top to a trivalent lanthanide dopant is then sufficient to construct a VRBE diagram with all lanthanide levels with respect to the vacuum level and the host valence and conduction bands.","Ce centroid shift; Charge transition levels; Electronegativity; Electronic structure; Lanthanides; VRBE-schemes","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:87e5685a-8445-46d2-8629-79a076dcdcb1","http://resolver.tudelft.nl/uuid:87e5685a-8445-46d2-8629-79a076dcdcb1","Effect of temperature on lanthanide charge transition levels and vacuum referred binding energies","Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2024","Location of lanthanide levels in the bandgap, vacuum referred binding energy (VRBE) in the lanthanide ground state and energy of lanthanide charge transition levels (CTLs) are just three different namings for the same concept. A concept of importance for the performance of lanthanide activated compounds. Energy differences of CTLs with the conduction band bottom and valence band top are important when it concerns e.g. lanthanide luminescence, charge carrier trapping, and valence stability. Effect of temperature on CTL energy or VRBE has so far never been addressed despite that luminescence application and thermoluminescence studies may span a temperature range from 10 K to 1000 K. In this work information on the bandgap (or energy of host exciton creation) around 10 K and at RT in compounds is gathered to demonstrate that bandgap decreases by 0.1 eV to 0.3 eV when temperature increases to RT. A similar decrease will be demonstrated for the energy of electron transfer from the VB to a trivalent lanthanide. The findings have consequences for VRBE-diagram construction, i.e. the experimental parameters for such construction should all apply to the same temperature. They also have consequences on how to relate luminescence thermal quenching energy barriers and TL derived electron and hole trap depths with a VRBE diagram. By proper evaluating the effects of temperature, accuracy of VRBE diagrams and consistency with luminescence and thermoluminescence data can be improved.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:edf67d8a-fc91-46c7-a195-809612dc5339","http://resolver.tudelft.nl/uuid:edf67d8a-fc91-46c7-a195-809612dc5339","Lengthening of the Sm2+ 4f55d → 4f6 decay time through interplay with the 4f6[5D0] level and its analogy to Eu2+ and Pr3+","van Aarle, C. (TU Delft RST/Luminescence Materials); Krämer, Karl W. (University of Bern); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2024","Recent research activity on Sm2+-doped compounds has significantly increased the amount of available data on 4f55d → 4f6 decay times. This enabled the systematic comparison of spectroscopic and time resolved luminescence data to theoretical models describing the interplay between the 4f55d and 4f6[5D0] excited states on the observed decay time. A Boltzmann distribution between the population of the excited states is assumed, introducing a dependence of the observed 4f55d → 4f6 decay time on the energy gap between the 4f55d and 4f6[5D0] levels and temperature. The model is used to interpret the origin of the large variation in reported 4f55d → 4f6 decay times through literature, and links their temperature dependence to applications such as luminescence thermometry and near-infrared scintillation. The model is further applied to the analogous situation of close lying 4fn-15d and 4fn states in Eu2+ (6P7/2) and Pr3+ (1S0).","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:1a534a77-ee67-4431-819a-1a50fe7cdd70","http://resolver.tudelft.nl/uuid:1a534a77-ee67-4431-819a-1a50fe7cdd70","Charge carrier trapping management in Bi3+ and lanthanides doped Li(Sc,Lu)GeO4 for x-ray imaging, anti-counterfeiting, and force recording","Lyu, Tianshuai (Huaqiao University); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2024","Discovering energy storage materials with rationally controlled trapping and de-trapping of electrons and holes upon x-rays, UV-light, or mechanical force stimulation is challenging. Such materials enable promising applications in various fields, for instance in multimode anti-counterfeiting, x-ray imaging, and non-real-time force recording. In this work, photoluminescence spectroscopy, the refined chemical shift model, and thermoluminescence studies will be combined to establish the vacuum referred binding energy (VRBE) diagrams for the LiSc1-xLuxGeO4 family of compounds containing the energy level locations of Bi2+, Bi3+, and the lanthanides. The established VRBE diagrams are used to rationally develop Bi3+ and lanthanides doped LiSc1-xLuxGeO4 storage phosphors and to understand trapping and de-trapping processes of charge carriers with various physical excitation means. The thermoluminescence intensity of x-ray irradiated LiSc0.25Lu0.75GeO4:0.001Bi3+,0.001Eu3+ is about two times higher than that of the state-of-the-art x-ray storage phosphor BaFBr(I):Eu2+. Particularly, a force induced charge carrier storage phenomenon appears in Eu3+ co-doped LiSc1-xLuxGeO4. Proof-of-concept non-real-time force recording, anti-counterfeiting, and x-ray imaging applications will be demonstrated. This work not only deepens our understanding of the capturing and de-trapping processes of electrons and holes with various physical excitation sources, but can also trigger scientists to rationally discover new storage phosphors by exploiting the VRBEs of bismuth and lanthanide levels.","","en","journal article","","","","","","","","2024-08-21","","","RST/Luminescence Materials","","",""
"uuid:c4bc3e36-596a-41c8-8b36-a5458e5afbe9","http://resolver.tudelft.nl/uuid:c4bc3e36-596a-41c8-8b36-a5458e5afbe9","Evaluating the Tm2+ 4f125d1 → 4f13 and 4f13 → 4f13 Luminescence and Quenching Dynamics in Orthorhombic BaCl2","Plokker, M.P. (TU Delft RST/Luminescence Materials); Vlaar, S.A. (Student TU Delft); Bakx, A.H.J. (Student TU Delft); van der Kolk, E. (TU Delft RST/Luminescence Materials); Dorenbos, P. (TU Delft RST/Luminescence Materials); Hintzen, H.T.J.M. (TU Delft RST/Luminescence Materials)","","2023","The luminescence properties of Tm2+-doped BaCl2 with an orthorhombic structure have been studied as a function of temperature and compared to other Tm2+-doped chlorides. In addition to the 2F5/2 → 2F7/2 (4f13 → 4f13) line emission, two 4f125d1 → 4f13 band emissions are observed at 20 K that can be ascribed to the spin-allowed (3H6,5d1)S=1/2 → 2F7/2 and spin-forbidden (3H6,5d1)S=3/2 → 2F7/2 transitions. So far, the Tm2+ spin-allowed (3H6,5d1)S=1/2 → 2F7/2 transition has only been identified in Tm2+-doped iodides and some bromides but never before in a Tm2+-doped chloride. Its presence in orthorhombic BaCl2:Tm2+ is explained by the absence of a (3H6,5d1)S=1/2 → (3H6,5d1)S=3/2 energy transfer process. As the temperature increases, both 4f125d1 → 4f13 emissions undergo rapid quenching and are no longer observed at 120 K, resulting in an intensity increase of the 4f13 → 4f13 emission. However, above 100 K, the intensity of the 4f13 → 4f13 emission also decreases, most likely due to quenching via (3H6,5d1)S=3/2 → 2F7/2 interband crossing, as enabled by the exceptionally large 4f125d1 Stokes shift.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:55467474-8aa1-48fa-bd0a-3cacc3b07fb9","http://resolver.tudelft.nl/uuid:55467474-8aa1-48fa-bd0a-3cacc3b07fb9","Avoiding concentration quenching and self-absorption in Cs4EuX6 (X = Br, I) by Sm2+ doping","van Aarle, C. (TU Delft RST/Luminescence Materials); Krämer, Karl W. (University of Bern); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2023","The benefits of doping Cs4EuBr6 and Cs4EuI6 with Sm2+ are studied for near-infrared scintillator applications. It is shown that undoped Cs4EuI6 suffers from a high probability of self-absorption, which is almost completely absent in Cs4EuI6:2% Sm. Sm2+ doping is also used to gain insight in the migration rate of Eu2+ excitations in Cs4EuBr6 and Cs4EuI6, which shows that concentration quenching is weak, but still significant in the undoped compounds. Both self-absorption and concentration quenching are linked to the spectral overlap of the Eu2+ excitation and emission spectra which were studied between 10 K and 300 K. The scintillation characteristics of Cs4EuI6:2% Sm is compared to that of the undoped samples. An improvement of energy resolution from 11% to 7.5% is found upon doping Cs4EuI6 with 2% Sm and the scintillation decay time shortens from 4.8 s to 3.5 s in samples of around 3 mm in size.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:87ae67b2-16e0-4e90-ad3d-42c3bc220b15","http://resolver.tudelft.nl/uuid:87ae67b2-16e0-4e90-ad3d-42c3bc220b15","Designing LiTaO3:Ln3+,Eu3+ (Ln = Tb or Pr) perovskite dosimeter with excellent charge carrier storage capacity and stability for anti-counterfeiting and flexible X-ray imaging","Lyu, Tianshuai (Huaqiao University, Xiamen); Dorenbos, P. (TU Delft RST/Luminescence Materials); Wei, Zhanhua (Huaqiao University, Xiamen)","","2023","Developing X-ray charged dosimeters with excellent charge carrier storage capacity and stability is challenging. Such energy storage dosimeters have fascinating use in developing novel applications, for instance, in radiation detection, advanced multimode anti-counterfeiting, and flexible X-ray imaging of curved objects. Herein, novel LiTaO3:Ln3+,Eu3+ (Ln = Tb or Pr) perovskite dosimeters are reported by combining the vacuum referred binding energy (VRBE) diagram of LiTaO3 and the optimization of dopant's concentration and compound synthesis condition. Based on the VRBE diagram prediction, charge carrier capturing and de-trapping processes in Eu3+ and/or Ln3+ (Ln = Tb or Pr) doped LiTaO3 will be studied to unravel the role of Eu3+ as a good electron trapping centre and to discover a record storage phosphor. The ratios of the thermoluminescence intensity of the optimized LiTaO3:0.005Tb3+,0.001Eu3+ to that of the state-of-the-art BaFBr(I):Eu2+, Al2O3:C, or NaLuF4:Tb3+ are 5.2, 8.8, or 2.8, respectively. The charge carriers can be stored more than 1000 h in LiTaO3:0.005Tb3+,0.001Eu3+. Proof-of-concept anti-counterfeiting application will be demonstrated by combining the colour-tailorable photoluminescence, afterglow, thermally, or optically stimulated luminescence in LiTaO3:0.005Tb3+,xEu3+ and LiTaO3:0.005Pr3+,0.001Eu3+. Multimode anti-counterfeiting application will be proposed by combining a high absolute X-ray scintillation light yield of 19000 ± 1800 ph/MeV of LiTaO3:0.005Tb3+,0.001Eu3+. Proof-of-concept flexible X-ray imaging application will be demonstrated by using the optimized LiTaO3:0.005Tb3+, 0.001Eu3+ dispersed in a silicone gel film.","Designing storage phosphors; Eu as a good electron trap; Flexible X-ray imaging; LiTaO:Ln,Eu (Ln=Tb or Pr) perovskite; Multimode anti-counterfeiting; VRBE diagram","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-08-02","","","RST/Luminescence Materials","","",""
"uuid:de51af49-7bc4-40d2-a467-2e4fb88760e1","http://resolver.tudelft.nl/uuid:de51af49-7bc4-40d2-a467-2e4fb88760e1","Measurements and computational analysis of the natural decay of Lu 176","Quarati, F.G.A. (TU Delft RST/Luminescence Materials; Gonitec BV, Den Haag); Bollen, G. (Michigan State University); Dorenbos, P. (TU Delft RST/Luminescence Materials); Eibach, M. (Greifswald University; Michigan State University); Gulyuz, K. (Central Michigan University, Mount Pleasant, Michigan); Hamaker, A. (Michigan State University); Izzo, C. (Michigan State University); Keblbeck, D. K. (Central Michigan University, Mount Pleasant, Michigan); Mougeot, X. (Université Paris-Saclay, Paris)","","2023","Background: Mainly because of its long half-life and despite its scientific relevance, spectroscopic measurements of Lu176 forbidden β decays are very limited and lack formulation of shape factors. A direct precise measurement of its Q value is also presently unreported. In addition, the description of forbidden decays provides interesting challenges for nuclear theory. The comparison of precise experimental results with theoretical calculations for these decays can help to test underlying models and can aid the interpretation of data from other experiments. Purpose: Perform the first precision measurements of Lu176β-decay spectra and attempt the observation of its electron capture decays, as well as perform the first precision direct measurement of the Lu176β-decay Q value. Compare the shape of the precisely determined experimental β spectra to theoretical calculations, and compare the end point energy to that obtained from an independent Q value measurement. Method: The Lu176β-decay spectra measurements and the search for electron capture decays were performed with an experimental setup that employed lutetium-containing scintillator crystals and a NaI(Tl) spectrometer for coincidence counting. The β decay Q value was determined via high-precision Penning trap mass spectrometry (PTMS) with the LEBIT facility at the National Superconducting Cyclotron Laboratory. The β-spectrum calculations were performed within the Fermi theory formalism with nuclear structure effects calculated using a shell model approach. Results: Both β transitions of Lu176 were experimentally observed and corresponding shape factors formulated in their entire energy ranges. The search for electron capture decay branches led to an experimental upper limit of 6.3×10-6 relative to its β decays. The Lu176β-decay and electron capture Q values were measured using PTMS to be 1193.0(6) and 108.9(8) keV, respectively. This enabled precise β end point energies of 596.2(6) and 195.3(6) keV to be determined for the primary and secondary β decays, respectively. The conserved vector current hypothesis was applied to calculate the relativistic vector matrix elements. The β-spectrum shape was shown to significantly depend on the Coulomb displacement energy and on the value of the axial vector coupling constant gA, which was extracted according to different assumptions. Conclusion: The implemented self-scintillation method has provided unmatched observations of Lu176, independently validated by the first direct measurements of its β-decay Q value by Penning trap mass spectrometry. Theoretical study of the main β transition led to the extraction of very different effective gA and log10f values, showing that a high-precision description of this transition would require a realistic nuclear structure with nucleus deformation.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:d5e757b9-f084-43dd-9e00-8dad372190ae","http://resolver.tudelft.nl/uuid:d5e757b9-f084-43dd-9e00-8dad372190ae","Cationic Effects on Photo- and X-ray Radioluminescence of K3RE(PO4)2:Ce3+/Pr3+ (RE = La, Gd, and Y) Phosphors toward X-ray Detection","Ou, Yiyi (Sun Yat-sen University); Zhou, Weijie (Sun Yat-sen University); Dorenbos, P. (TU Delft RST/Luminescence Materials); Liang, Hongbin (Sun Yat-sen University)","","2023","Cationic tuning for lanthanide (Ce3+/Pr3+)-activated inorganic phosphors with stable, efficient, and fast-decay 5d-4f emissions has emerged as an important strategy toward the continuing pursuit of superior scintillators. The in-depth understanding of the cationic effects on photo- and radioluminescence of lanthanides Ce3+ and Pr3+ centers is requisite for the rational cationic tuning. Here, we perform a systematic study on the structure and photo- and X-ray radioluminescence properties of K3RE(PO4)2:Ce3+/Pr3+ (RE = La, Gd, and Y) phosphors to elucidate the underlying cationic effects on their 4f-5d luminescence. By using the Rietveld refinements, low-temperature synchrotron-radiation vacuum ultraviolet-ultraviolet spectra, vibronic coupling analyses, and vacuum-referred binding energy schemes, the origins of lattice parameter evolutions, 5d excitation energies, 5d emission energies, and Stokes shifts as well as good emission thermal stabilities of K3RE(PO4)2:Ce3+ systems are revealed. In addition, the correlations of Pr3+ luminescence to Ce3+ in the same sites are also discussed. Finally, the X-ray excited luminescence manifests that the K3Gd(PO4)2:1%Ce3+ sample possesses a light yield of ∼10,217 photons/MeV, indicating its potentiality toward X-ray detection application. These results deepen the understanding of cationic effects on Ce3+ and Pr3+ 4f-5d luminescence and inspire the inorganic scintillator development.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-10-05","","","RST/Luminescence Materials","","",""
"uuid:36fccfe2-ede3-4500-85cc-0957b5348eda","http://resolver.tudelft.nl/uuid:36fccfe2-ede3-4500-85cc-0957b5348eda","Light yield and thermal quenching of Ce3+ and Pr3+ co-doped LaBr3:Sm2+ near-infrared scintillators","van Aarle, C. (TU Delft RST/Luminescence Materials); Roturier, Nils (Student TU Delft); Biner, Daniel A. (University of Bern); Krämer, Karl W. (University of Bern); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2023","LaBr3:Ce3+ is a compound with excellent scintillation properties, but its ultraviolet emission does not match well with the detection efficiency curves of silicon based photodetectors. In this work, Sm2+ is studied as an activator for LaBr3 as its near-infrared emission can be detected with close to 100% efficiency by such photodetectors. LaBr3:Sm2+ single crystals were grown with and without co-doping of Ce3+ or Pr3+. The samples were studied by means of X-ray excited and photoluminescence spectroscopy at temperatures between 10 K and 300 K. Their spectroscopic properties are compared to LaBr3:Ce3+ and LaBr3:Eu2+. The effect of using Ce3+ or Pr3+ as scintillation sensitiser for Sm2+ is assessed. It is found that energy transfer from host to Sm2+ greatly improves upon Ce3+ co-doping, but the quenching temperature of the Sm2+ emission decreases. The quenching mechanism of both the Ce3+ and Sm2+ emission in LaBr3 is elaborated on. Furthermore, the effect of charge compensating defects on the light yield and spectroscopic properties is discussed.","Divalent samarium; Near-infrared emission; Scintillation; Single crystal","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:02aa816d-4821-4f9e-b49e-dcc8106c0f43","http://resolver.tudelft.nl/uuid:02aa816d-4821-4f9e-b49e-dcc8106c0f43","Scintillation and Optical Characterization of CsCu2I3 Single Crystals from 10 to 400 K","van Blaaderen, J.J. (TU Delft RST/Luminescence Materials); van den Brekel, Liselotte A. (Student TU Delft); Krämer, Karl W. (University of Bern); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2023","Currently only Eu2+-based scintillators have approached the light yield needed to improve the 2% energy resolution at 662 keV of LaBr3:Ce3+,Sr2+. Their major limitation, however, is the significant self-absorption due to Eu2+. CsCu2I3 is an interesting new small band gap scintillator. It is nonhygroscopic and nontoxic, melts congruently, and has an extremely low afterglow, a density of 5.01 g/cm3, and an effective atomic number of 50.6. It shows self-trapped exciton emission at room temperature. The large Stokes shift of this emission ensures that this material is not sensitive to self-absorption, tackling one of the major problems of Eu2+-based scintillators. An avalanche photo diode, whose optimal detection efficiency matches the 570 nm mean emission wavelength of CsCu2I3, was used to measure pulse height spectra. From the latter, a light yield of 36 000 photons/MeV and energy resolution of 4.82% were obtained. The scintillation proportionality of CsCu2I3 was found to be on par with that of SrI2:Eu2+. Based on temperature-dependent emission and decay measurements, it was demonstrated that CsCu2I3 emission is already about 50% quenched at room temperature. Using temperature-dependent pulse height measurements, it is shown that the light yield can be increased up to 60 000 photons/MeV by cooling to 200 K, experimentally demonstrating the scintillation potential of CsCu2I3.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:a0261330-f0c1-42ac-b892-2c5312dc072c","http://resolver.tudelft.nl/uuid:a0261330-f0c1-42ac-b892-2c5312dc072c","(BZA)2PbBr4: A potential scintillator for photon-counting computed tomography detectors","van Blaaderen, J.J. (TU Delft RST/Luminescence Materials); van der Sar, S.J. (TU Delft RST/Medical Physics & Technology); Onggo, Djulia (Institute of Technology Bandung); Sheikh, Md Abdul K. (PORT Polish Center for Technology Development, Wroclaw); Schaart, D.R. (TU Delft RST/Medical Physics & Technology; Holland Particle Therapy Centre); Birowosuto, Muhammad D. (PORT Polish Center for Technology Development, Wroclaw); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2023","Due to recent development in detector technology, photon-counting computed tomography (PCCT) has become a rapidly emerging medical imaging technology. Current PCCT systems rely on the direct conversion of X-ray photons into charge pulses, using CdTe, CZT, or Si semiconductor detectors. Indirect detection using ultrafast scintillators coupled to silicon photomultipliers (SiPM) offers a potentially more straightforward and cost-effective alternative. In this work a new 2D perovskite scintillator, benzylamonium lead bromide (BZA)2PbBr4, is experimentally characterised as function of temperature. The material exhibits a 4.2 ns decay time under X-ray excitation at room temperature and a light yield of 3700 photons/MeV. The simulation tool developed by Van der Sar et al. was used to model the pulse trains produced by a SiPM-based (BZA)2PbBr4 detector. The fast decay time of (BZA)2PbBr4 results in outstanding count-rate performance as well as very low statistical fluctuations in the simulated pulses. These features of (BZA)2PbBr4, combined with its cost-effective synthesis make (BZA)2PbBr4 very promising for PCCT.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:a0660720-6c1a-41fb-8565-bf68035e1fdc","http://resolver.tudelft.nl/uuid:a0660720-6c1a-41fb-8565-bf68035e1fdc","Hole Detrapping-Type Persistent Phosphors of RE2O2S (RE = La, Gd, Y, Lu) Doped with Eu3+-Pr3+ and Eu3+-Tb3+","Hashimoto, Atsunori (Japan Advanced Institute of Science and Technology; NEMOTO & CO.); Ueda, Jumpei (Japan Advanced Institute of Science and Technology; Kyoto University); Aoki, Yasushi (NEMOTO & CO.); Dorenbos, P. (TU Delft RST/Luminescence Materials); Tanabe, Setsuhisa (Kyoto University)","","2023","RE2O2S:Eu3+-Ln3+ (RE = La, Gd, Y, Lu; Ln = Pr, Tb) samples were prepared by a solid-state reaction method to develop new red persistent phosphors and to demonstrate the hole detrapping mechanism. All Eu3+-singly doped RE2O2S show very weak thermoluminescence (TL) glow peaks, while by codoping Pr3+ or Tb3+ ions, additional strong TL peaks were observed. In the TL spectra and persistent luminescence (PersL) spectra, only Eu3+ luminescence lines were observed, but there was no Pr3+ and Tb3+ luminescence. From the PersL excitation spectra, it is found that PersL is caused after excitation to the charge transfer state of Eu2+-S- in which the hole is in the valence band. These results show that Eu3+ acts as a recombination center and Pr3+ and Tb3+ ions act as hole trap centers. The deeper hole trap depth of Pr3+ than that of Tb3+ and the RE dependence of hole trap depth are explained using a vacuum referred binding energy diagram considering the nephelauxetic effect. La2O2S:Eu3+-Pr3+ was the best composition among the samples as a persistent phosphor at ambient temperature, showing strong red persistent luminescence in a short time range (>100 mcd/m2 for a few seconds).","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-01-26","","","RST/Luminescence Materials","","",""
"uuid:95ac9c63-2b27-48f7-9e55-bb03c41dfd63","http://resolver.tudelft.nl/uuid:95ac9c63-2b27-48f7-9e55-bb03c41dfd63","Versatile and High-Performance LiTaO3:Tb3+, Gd3+ Perovskite for Multimode Anti-counterfeiting, Flexible X-Ray Imaging, Continuous Stress Sensing, and Non-Real-Time Recording","Lyu, Tianshuai (Huaqiao University); Dorenbos, P. (TU Delft RST/Luminescence Materials); Wei, Zhanhua (Huaqiao University)","","2023","Multimode luminescence relates to how charge carriers are transported and recombined in response to various physical excitations. It shows promising applications in many fields like advanced anti-counterfeiting, information storage and encryption. Enabling a stable single compound with multimode luminescence is a unique technology but still remains a challenge. Herein, a versatile and high-performance energy storage LiTaO3:0.01Tb3+,xGd3+ perovskite is discovered by utilizing the interplay of electron-trapping defect levels and hole-trapping Tb3+. It combines an excellent charge carrier storage capacity (≈7 and 12 times higher than state-of-the-art BaFBr(I):Eu2+ and Al2O3:C), >1200 h storage duration, >40 h afterglow, efficient optically stimulated luminescence, persistent mechanoluminescence, and force-induced charge carrier storage features. Particularly, it well responds to various stimuli channels, i.e., wide-range X-rays to 850 nm infrared photons, thermal activation, mechanical force grinding, or compression. To elucidate this multimode luminescence, charge carrier trapping and release processes in LiTaO3:0.01Tb3+,xGd3+ with various physical stimulations will be unraveled by combining the vacuum-referred binding diagram construction, spectroscopy, thermoluminescence, and mechanoluminescence techniques. The versatile and high-performance LiTaO3:0.01Tb3+,xGd3+ enables promising proof-of-concept multimode luminescence applications in advanced anti-counterfeiting, flexible X-ray imaging, continuous compression force sensing, and non-real-time recording.","advanced anti-counterfeiting; continuous stress sensing; flexible X-ray imaging; LiTaO:Tb,Gd perovskite; Multimode luminescence; non-real-time stress recording","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-03-22","","","RST/Luminescence Materials","","",""
"uuid:f625feb8-e609-4d5e-a5a6-b1e8b40121c0","http://resolver.tudelft.nl/uuid:f625feb8-e609-4d5e-a5a6-b1e8b40121c0","Thermal quenching of lanthanide luminescence via charge transfer states in inorganic materials","Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2022","There are various routes of luminescence quenching such as multi-phonon relaxation from excited states to lower energy states, energy migration to killer sites, and radiation less relaxation to the ground state via the crossing point in a configurational coordinate diagram. In this work, we will consider and review quenching of lanthanide luminescence by means of charge carrier transfer to the valence band or the conduction band of the host compound. We will focus on 4fn-4fn emission quenching due to thermally activated electron transfer from the Pr3+ 3P0 level and the Tb3+ 5D4 level to the conduction band, and due to thermally activated hole transfer from the Eu3+ 5D0 level to the valence band. In addition, we will consider the quenching of the 4fn−15d-4fn emission of Eu2+ and Ce3+ which often (if not always) proceeds by electron transfer to the conduction band. Since all the above quenching routes involve reduction or oxidation of lanthanides, the location of the lanthanide charge transition levels with respect to the host bands is crucial. In other words, we need to know the location of the ground and excited states in the band gap or equivalently the vacuum referred binding energies (VRBE) in the lanthanide states as can be established using the (refined) chemical shift model. A clear correlation between the temperature T50 at which luminescence intensity or luminescence decay time has dropped by 50% and thermal quenching activation energies ΔE derived from VRBE schemes will be demonstrated. Since T50 typically changes 400-800 K with a 1 eV change in ΔE, and since VRBE energies may contain 0.3-0.5 eV error, it will be clear that the accurate prediction of quenching temperatures from the VRBE data is not yet feasible. Nevertheless, one may derive trends and provide guidelines on how to improve the thermal stability of luminescence.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:57cb2a92-5345-4747-97ec-8b9e1c5cd911","http://resolver.tudelft.nl/uuid:57cb2a92-5345-4747-97ec-8b9e1c5cd911","Unraveling electron liberation from Bi2+ for designing Bi3+-based afterglow phosphor for anti-counterfeiting and flexible X-ray imaging","Lyu, T. (TU Delft RST/Luminescence Materials); Dorenbos, P. (TU Delft RST/Luminescence Materials); Li, Canhua (Huaqiao University, Xiamen); Li, Silei (Huaqiao University, Xiamen); Xu, Jian (National Institute for Materials Science); Wei, Zhanhua (Huaqiao University, Xiamen)","","2022","It is challenging to rational design persistent luminescence and storage phosphors with high storage capacity of electrons and holes after X-ray charging. Such phosphors have potential applications in anti-counterfeiting and X-ray imaging. Here we have combined vacuum referred binding energy diagram (VRBE) construction, photoluminescence spectroscopy, and thermoluminescence to study the trapping processes of charge carriers in NaYGeO4. In NaYGeO4:0.004Bi3+ and NaYGeO4:0.004Bi3+,0.005Ln3+ (Ln = Tb or Pr), Bi3+ appears to act as a shallow electron trap, while Bi3+ and Ln3+ act as deep hole trapping and recombination centres. We will show how to experimentally determine the VRBE in the Bi2+ 2P1/2 ground state in NaYGeO4 and NaLuGeO4 by thermoluminescence study. The electron trap depth produced by Bi3+ codopant in NaLu1-xYxGeO4:0.003Bi3+,0.008 Tb3+ can be adjusted, by increasing x, resulting in conduction band engineering. By combining Bi3+ as an electron trap and Bi3+ and Tb3+ as the hole traps, excellent X-ray charged afterglow phosphors were developed. The integrated TL intensity of the optimized NaYGeO4:0.004Bi3+ and NaYGeO4:0.003Bi3+,0.008Tb3+ after exposure to X-rays is about 4.5 and 1.1 times higher than that of the state-of-the-art BaFBr(I):Eu2+ storage phosphor. Intense initial Tb3+ 4f → 4f afterglow appears in NaYGeO4:0.003Bi3+,0.008Tb3+ and more than 40 h afterglow is measurable in NaYGeO4:0.004Bi3+ and NaYGeO4:0.003Bi3+, 0.008 Tb3+ after X-ray charging. We will show proof-of-concept anti-counterfeiting and X-ray imaging applications by using the developed afterglow phosphors and CsPbI3 quantum dots. This work not only provides experimental evidence on the VRBE in the Bi2+ 2P1/2 ground state in NaYGeO4, but also shows how to design and develop good afterglow phosphors for anti-counterfeiting and X-ray imaging by deeply studying and controlling the trapping processes of charge carriers in bismuth and/or lanthanides doped inorganic compounds.","Bi VRBE; Bismuth; Electron liberation from Bi; Electron trap depth engineering; X-ray imaging","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","RST/Luminescence Materials","","",""
"uuid:c3a92c3e-0bac-44ea-b941-3ccbdfe86ea6","http://resolver.tudelft.nl/uuid:c3a92c3e-0bac-44ea-b941-3ccbdfe86ea6","Efficient mid-infrared single-photon detection using superconducting NbTiN nanowires with high time resolution in a Gifford-McMahon cryocooler","Chang, J. (TU Delft QN/Groeblacher Lab; Single Quantum); Los, Johannes W.N. (Single Quantum); Gourgues, Ronan (Single Quantum); Steinhauer, Stephan (AlbaNova University Center); Dorenbos, S.N. (Single Quantum); Pereira, S.F. (TU Delft ImPhys/Optics); Urbach, Paul (TU Delft ImPhys/Optics); Zwiller, Val (AlbaNova University Center); Esmaeil Zadeh, I.Z. (TU Delft ImPhys/Optics)","","2022","Shortly after their inception, superconducting nanowire single-photon detectors (SNSPDs) became the leading quantum light detection technology. With the capability of detecting single-photons with near-unity efficiency, high time resolution, low dark count rate, and fast recovery time, SNSPDs outperform conventional single-photon detection techniques. However, detecting lower energy single photons (<0.8 eV) with high efficiency and low timing jitter has remained a challenge. To achieve unity internal efficiency at mid-infrared wavelengths, previous works used amorphous superconducting materials with low energy gaps at the expense of reduced time resolution (close to a nanosecond), and by operating them in complex milliKelvin (mK) dilution refrigerators. In this work, we provide an alternative approach with SNSPDs fabricated from 5 to 9.5 nm thick NbTiN superconducting films and devices operated in conventional Gifford-McMahon cryocoolers. By optimizing the superconducting film deposition process, film thickness, and nanowire design, our fiber-coupled devices achieved >70% system detection efficiency (SDE) at 2 μm and sub-15 ps timing jitter. Furthermore, detectors from the same batch demonstrated unity internal detection efficiency at 3 μm and 80% internal efficiency at 4 μm, paving the road for an efficient mid-infrared single-photon detection technology with unparalleled time resolution and without mK cooling requirements. We also systematically studied the dark count rates (DCRs) of our detectors coupled to different types of mid-infrared optical fibers and blackbody radiation filters. This offers insight into the trade-off between bandwidth and DCRs for mid-infrared SNSPDs. To conclude, this paper significantly extends the working wavelength range for SNSPDs made from polycrystalline NbTiN to 1.5-4 μm, and we expect quantum optics experiments and applications in the mid-infrared range to benefit from this far-reaching technology.","","en","journal article","","","","","","","","","","","QN/Groeblacher Lab","","",""
"uuid:88f10136-8307-4529-b4b1-aa4a4f42fa05","http://resolver.tudelft.nl/uuid:88f10136-8307-4529-b4b1-aa4a4f42fa05","Vacuum-Referred Binding Energies of Bismuth and Lanthanide Levels in LiTaO3 Perovskite: Toward Designing Energy Storage Phosphor for Anti-Counterfeiting, X-Ray Imaging, and Mechanoluminescence","Lyu, Tianshuai (Huaqiao University, Xiamen); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2022","Discovering UV-light or X-ray charged afterglow and storage phosphors with high charge carrier storage capacity remains challenging. Herein, a method is proposed by combining vacuum referred binding energy (VRBE) diagram construction and optimization of dopants’ concentration and compound synthesis. The refined chemical shift model, optical spectroscopy, and thermoluminescence will be combined to construct the VRBE diagram of LiTaO3 with the lanthanide and bismuth charge transition levels. Based on the constructed VRBE diagram of LiTaO3, Bi3+, and/or Ln3+ (Ln = Tb or Pr) doped LiTaO3 will be studied. By combining Bi3+ with Tb3+, Pr3+, or Bi3+ itself, Bi3+ emerges to act as a ≈0.62 eV deep electron trap, while Tb3+, Pr3+, or Bi3+ acts as about 1.5 eV deep hole capturing and recombination centres. The VRBE in the Bi2+ 2P1/2 ground state will be derived by thermoluminescence study. Proof-of-concept X-ray imaging, compression force distribution monitoring, and color-tailoring for anti-counterfeiting will be demonstrated by using the developed Bi3+ and/or Ln3+ doped LiTaO3. This work promotes the understanding of trap level locations and on the trapping and release processes of charge carriers in Bi3+ and/or lanthanides doped inorganic compounds for rational design of new afterglow and storage phosphors.","Bi; electron release from Bi; mechanoluminescence; VRBE; X-ray imaging","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","RST/Luminescence Materials","","",""
"uuid:73a45260-d7d9-410c-935f-8b59bb02a428","http://resolver.tudelft.nl/uuid:73a45260-d7d9-410c-935f-8b59bb02a428","Temperature dependent scintillation properties and mechanisms of (PEA)2PbBr4 single crystals","van Blaaderen, J.J. (TU Delft RST/Luminescence Materials); Maddalena, Francesco (Nanyang Technological University); Dang, Cuong (Nanyang Technological University); Birowosuto, Muhammad Danang (PORT Polish Center for Technology Development, Wroclaw); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2022","In this work the scintillation properties of PEA2PbBr4 are studied as function of temperature, accessing the potential use of these materials for low temperature applications. The scintillation properties and mechanism have been studied using a combination of temperature dependent photoluminescence emission and excitation, X-ray excited emission and decay measurements. At room temperature the X-ray excited emission is dominated by the 442 nm emission with a lifetime of 35.2 ns. Under UV-Vis photon excitation an additional emission peak is observed at 412 nm. At 10 K, both X-ray and UV-Vis photon excited emission spectra show a narrow emission peak at 412 nm and a broad emission band centred around 525 nm with a lifetime of 1.53 ns (24%) and 154 ns (76%) respectively. The exact nature of the observed emission peaks is not known. For this reason two potential mechanisms explaining the difference between UV-Vis photon and X-ray excitation and their temperature dependent emissions are explored. The total spectral intensity decreases to 72% of the intensity at room temperature at 10 K. It is suggested that the observed negative thermal quenching behaviour results from a combination of more self absorption and a higher degree of self trapped exciton formation under X-ray excitation. Based on the observed fast decay component at 10 K and light yield of 9400 photons per MeV at room temperature, showing only a 28% decrease at 10 K, could make this material potentially interesting for low temperature and fast timing applications.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:cf28a6f2-2bf4-4cde-973f-f91d438fd73d","http://resolver.tudelft.nl/uuid:cf28a6f2-2bf4-4cde-973f-f91d438fd73d","Characterisation of Sm2+-doped CsYbBr3, CsYbI3 and YbCl2 for near-infrared scintillator application","van Aarle, C. (TU Delft RST/Luminescence Materials); Krämer, Karl W. (University of Bern); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2022","Fast energy transfer from Yb2+ to Sm2+ is a requirement when using Yb2+ as a sensitiser for Sm2+ emission for near-infrared scintillator applications. This cannot be achieved through dipole-dipole interactions due to the spin-forbidden nature of the involved Yb2+ transition, making the rate of energy transfer too slow for application. This work explores whether exploiting the exchange interaction by increasing the Yb2+ concentration to 99% is an effective way to increase the rate at which energy is transferred from Yb2+ to Sm2+. The scintillation characteristics of CsYbBr3:1%Sm, CsYbI3:1%Sm and YbCl2:1%Sm single crystals were studied through 137Cs excited pulse height spectra, X-ray excited decay and X-ray excited luminescence spectra. An energy resolution of 7% and a light yield of 30,000 ph/MeV was achieved with CsYbI3:1%Sm. Photoluminescence spectroscopy and decay studies were performed to study the band structure and relaxation dynamics.","Divalent samarium; Divalent ytterbium; Energy transfer; Near-infrared scintillator; Single crystal","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:2b45ba93-2a75-479d-8f02-05d0468dcfcc","http://resolver.tudelft.nl/uuid:2b45ba93-2a75-479d-8f02-05d0468dcfcc","LiTaO3:Bi3+,Tb3+,Ga3+,Ge4+: A Smart Perovskite with High Charge Carrier Storage Capacity for X-Ray Imaging, Stress Sensing, and Non-Real-Time Recording","Lyu, Tianshuai (Huaqiao University, Xiamen); Dorenbos, P. (TU Delft RST/Luminescence Materials); Xiong, Puxian (South China University of Technology); Wei, Zhanhua (Huaqiao University, Xiamen)","","2022","Developing X-ray or UV-light charged storage and mechanoluminescence (ML) materials with high charge carrier storage capacity is challenging. Such materials have promising utilization in developing new applications, for example, in flexible X-ray imaging, stress sensing, or non-real-time recording. Herein, the study reports on such materials; Bi3+, Tb3+, Ga3+, or Ge4+ doped LiTaO3 perovskite storage and ML phosphors. Their photoluminescence, thermoluminescence (TL), and ML properties are studied. The charge carrier trapping and release processes in the Bi3+, Tb3+, Ga3+, or Ge4+ doped LiTaO3 are explained by using the constructed vacuum referred binding energy diagram of LiTaO3 including the energy level locations of unintended defects, Tb3+, Bi3+, and Bi2+. The ratio of the TL intensity after X-ray charging of the optimized LiTaO3:0.005Bi3+,0.006Tb3+,0.05Ga3+, or LiTaO3:0.005Bi3+,0.006Tb3+,0.05Ge4+ to that of the state-of-the-art BaFBr(I):Eu2+ is ≈1.2 and 2.7, respectively. Force induced charge carrier storage phenomena is studied in the Tb3+, Bi3+, Ga3+, or Ge4+ doped LiTaO3. Proof-of-concept compression force distribution sensing and X-ray imaging is demonstrated by using optimized LiTaO3:0.005Bi3+,0.006Tb3+,0.05Ga3+ dispersed in a hard epoxy resin disc and in a silicone gel film. Proof-of-concept color-tailorable ML for anti-counterfeiting is demonstrated by admixing commercial ZnS:Cu+,Mn2+ with optimized LiTaO3:0.005Bi3+,0.006Tb3+,0.05Ge4+ in an epoxy resin disc.","Bi; color-tailorable mechanoluminescence; force induced charge carrier storage; LiTaO perovskites; Tb; X-ray imaging","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","RST/Luminescence Materials","","",""
"uuid:68620f98-3ed5-48ae-8fd1-05c5442a93cd","http://resolver.tudelft.nl/uuid:68620f98-3ed5-48ae-8fd1-05c5442a93cd","Wide Range X-Ray to Infrared Photon Detection and Energy Storage in LiTaO3:Bi3+,Dy3+ Perovskite","Lyu, Tianshuai (Huaqiao University, Xiamen); Dorenbos, P. (TU Delft RST/Luminescence Materials); Li, Canhua (Huaqiao University, Xiamen); Wei, Zhanhua (Huaqiao University, Xiamen)","","2022","It is challenging to obtain a material that can detect photons ranging from X-rays to infrared light. Such materials have promising use to develop advanced applications like in information storage, anticounterfeiting, or X-ray imaging. This article reports on such a material; LiTaO3:xBi3+,yDy3+ perovskite phosphor. Experimental spectroscopy, thermoluminescence, and vacuum referred binding energy diagram (VRBE) construction are combined to study the trapping processes of charge carriers. The VRBEs in the ground or excited states of Bi3+ and Bi2+ are discussed. Bi3+ emerges to act as a ≈1.3 eV deep hole capturing center and it may possibly also act as a 0.80 ± 0.5 eV deep electron trapping center. A linear relation between the amount of stored charge carriers and a photochromic phenomenon both induced by X-rays or 254 nm UV-light charging appears. The stored charge carriers in LiTaO3:xBi3+,yDy3+ are removed by heating or with an optically stimulated process with 365 nm UV light to 850 nm infrared laser. More than 3 or 40 h of Bi3+ and Dy3+ based white afterglow is measurable in LiTaO3:0.005Bi3+,0.004Dy3+ after exposure to X-rays or 254 nm UV light. Proof-of-concept light detection applications like 2D information storage and anticounterfeiting or X-ray imaging are demonstrated by using the phtotochromic and white afterglow LiTaO3:xBi3+,yDy3+ phosphors.","bismuth; information storage and X-ray imaging; LiTaO perovskite; photochromic phenomena; white persistent luminescence","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","RST/Luminescence Materials","","",""
"uuid:04921136-2bd0-4889-82f1-6c04d891f049","http://resolver.tudelft.nl/uuid:04921136-2bd0-4889-82f1-6c04d891f049","Experimental and Theoretical Studies of the Site Occupancy and Luminescence of Ce3+in LiSr4(BO3)3for Potential X-ray Detecting Applications","Yang, Yunlin (Sun Yat-sen University); Lou, Bibo (University of Science and Technology of China); Ou, Yiyi (Sun Yat-sen University); Su, Fang (Sun Yat-sen University); Ma, Chong Geng (Chongqing University of Posts and Telecommunications); Duan, Chang Kui (University of Science and Technology of China); Dorenbos, P. (TU Delft RST/Luminescence Materials); Liang, Hongbin (Sun Yat-sen University)","","2022","Ce3+-doped LiSr4(BO3)3 phosphors have been prepared by a high-temperature solid-state reaction method, and structural refinement of the host compound has been performed. The excitation and emission spectra in the vacuum ultraviolet-ultraviolet-visible range at cryogenic temperatures reveal that Ce3+ ions preferentially occupy eight-coordinated Sr2+ sites in LiSr4(BO3)3. Such experimental attribution is well corroborated by the calculated 4f-5d transition energies and defect formation energies of Ce3+ ions at two distinct Sr2+ sites in the first-principles framework. In addition, the doping concentration-dependent luminescence and the temperature-dependent luminescence are systematically investigated by luminescence intensity and lifetime measurements, respectively. This shows that concentration quenching does not occur in the investigated doping range, but inhomogeneous broadening exists in the concentrated samples. With the estimated thermal quenching activation energy, the discussions on the thermal quenching mechanisms suggest that the thermal-ionization process of the 5d electron is a dominant channel for thermal quenching of Ce3+ luminescence, despite the fact that thermally activated concentration quenching cannot be excluded for the highly doped samples. Finally, the X-ray excited luminescence measurement demonstrates the promising applications of the phosphors in X-ray detection.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-11-05","","","RST/Luminescence Materials","","",""
"uuid:b36101d9-816f-4eed-a79d-d47113b7f1b6","http://resolver.tudelft.nl/uuid:b36101d9-816f-4eed-a79d-d47113b7f1b6","VUV-UV-vis photoluminescence, X-ray radioluminescence and energy transfer dynamics of Ce3+ and Eu2+ in Sr2MgSi2O7","Wen, Donghao (Sun Yat-sen University); Li, Quanfeng (Sun Yat-sen University); Ou, Yiyi (Sun Yat-sen University); Yang, Yunlin (Sun Yat-sen University); Qi, Zeming (University of Science and Technology of China); Dorenbos, P. (TU Delft RST/Luminescence Materials); Liang, Hongbin (Sun Yat-sen University)","","2022","Ce3+ and Eu2+ doped and Ce3+-Eu2+ co-doped Sr2MgSi2O7 phosphors are prepared via a high-temperature solid-state reaction technique. The synchrotron radiation vacuum ultraviolet-ultraviolet (VUV-UV) excitation and ultraviolet-visible (UV-vis) emission spectra of diluted Ce3+ and Eu2+ doped Sr2MgSi2O7 samples are measured at cryogenic temperatures. The electron-vibrational interaction (EVI) between Ce3+ and its surroundings is analyzed. The dependencies of the 4f-5d transitions of Ce3+ on the structure of the host compounds Sr2MgSi2O7, Ba2MgSi2O7 and BaMg2Si2O7 are discussed in detail. Then the thermal quenching channel is proposed based on the measurements of temperature dependent luminescence intensities and decay times of Ce3+ and Eu2+ in Sr2MgSi2O7, and the Ce3+ → Eu2+ energy transfer mechanism is understood by three luminescence dynamic models. In addition, Sr2MgSi2O7:Ce3+/Eu2+ samples are evaluated for the possibilities of X-ray detection applications using X-ray excited luminescence (XEL) spectroscopy, and it was found that they are not suitable.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","RST/Luminescence Materials","","",""
"uuid:16b6829d-3acc-4ca0-8149-53d8c0587293","http://resolver.tudelft.nl/uuid:16b6829d-3acc-4ca0-8149-53d8c0587293","Electronic structure of bi-activated luminescent compounds and pure bismuth photocatalytic compounds","Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2021","The trends in electronic structure of Bi3+ and Bi2+ as luminescent dopant in wide bandgap inorganic compounds and that of pure Bicompounds for photocatalytic splitting of water are explored by determination of vacuum referred electron binding energies. Spectroscopic data combined with the chemical shift model from the luminescence field and data on flatband potentials in electrochemistry provide most of the needed data. Occasionally data from photoelectron spectroscopy is used. The trends in VRBE of Bi3+ and Bi2+ ground state and excited state levels resemble that of Ce3+ and Eu2+ lanthanides. To some extend a pure Bi-compound can be regarded as a 100% Bi3+ doped La-compound. This all will be demonstrated and an overview on Bi electronic structure is presented. Comparison of electronic structure for Bi as luminescent dopant in inorganic compounds with pure Bi-compounds entails also a comparison of two disciplines in electro-chemistry, that of luminescence materials and of photo-catalytic compounds.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:22e1d753-b419-4f13-a78b-37f3979fc72f","http://resolver.tudelft.nl/uuid:22e1d753-b419-4f13-a78b-37f3979fc72f","Detecting telecom single photons with 99.5 - 2.07 + 0.5 % system detection efficiency and high time resolution","Chang, J. (TU Delft ImPhys/Optics; Single Quantum); Los, J. W.N. (Single Quantum); Tenorio Pearl, J.O. (Single Quantum); Noordzij, N. (Single Quantum); Gourgues, R.B.M. (Single Quantum); Guardiani, A. (Single Quantum); Zichi, J. R. (KTH Royal Institute of Technology); Pereira, S.F. (TU Delft ImPhys/Optics); Urbach, Paul (TU Delft ImPhys/Optics); Zwiller, V. (Single Quantum; KTH Royal Institute of Technology); Dorenbos, S.N. (Single Quantum); Esmaeil Zadeh, I.Z. (TU Delft ImPhys/Optics; Single Quantum)","","2021","Single photon detectors are indispensable tools in optics, from fundamental measurements to quantum information processing. The ability of superconducting nanowire single photon detectors (SNSPDs) to detect single photons with unprecedented efficiency, short dead time, and high time resolution over a large frequency range enabled major advances in quantum optics. However, combining near-unity system detection efficiency (SDE) with high timing performance remains an outstanding challenge. In this work, we fabricated novel SNSPDs on membranes with 99.5-2.07+0.5% SDE at 1350 nm with 32 ps timing jitter (using a room-temperature amplifier), and other detectors in the same batch showed 94%-98% SDE at 1260-1625 nm with 15-26 ps timing jitter (using cryogenic amplifiers). The SiO2/Au membrane enables broadband absorption in small SNSPDs, offering high detection efficiency in combination with high timing performance. With low-noise cryogenic amplifiers operated in the same cryostat, our efficient detectors reach a timing jitter in the range of 15-26 ps. We discuss the prime challenges in optical design, device fabrication, and accurate and reliable detection efficiency measurements to achieve high performance single photon detection. As a result, the fast developing fields of quantum information science, quantum metrology, infrared imaging, and quantum networks will greatly benefit from this far-reaching quantum detection technology.","","en","journal article","","","","","","","","","","","ImPhys/Optics","","",""
"uuid:dd14c7ed-8f73-4154-a93f-a839872b6fe4","http://resolver.tudelft.nl/uuid:dd14c7ed-8f73-4154-a93f-a839872b6fe4","Blasse's Pandora's box","Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2021","Upon his retirement from science Blasse wrote a paper (Blasse, J. Lumin. 72-74 (1997) 129) addressing unsolved problems in explaining luminescence phenomena of classical phosphors. He used the metaphor of Pandora's box. A box full of disaster that should remain closed. Yet, Blasse did open that box and therewith spread the unsolved problems over the luminescence community. Only the hope to solve those problems remained inside the box. Today, 25 years later, we will explore whether the hope has managed to provide answers. The unsolved problems related to the fundamental understanding of luminescence from WO42−, VO43−, Sb3+, Bi2+, Bi3+, Cu+, and Ce3+. Here we will show how vacuum referred binding energy diagrams can explain or can help to explain Blasse's unsolved problems of 1997.","Bismuth luminescence; Electron transfer; Quenching phenomena","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:2235501a-5ecc-4c13-a8f6-e98dfe28546d","http://resolver.tudelft.nl/uuid:2235501a-5ecc-4c13-a8f6-e98dfe28546d","Experimental and numerical analysis of Tm2+ excited-states dynamics and luminescence in CaX2 (X = Cl, Br, I)","Plokker, M.P. (TU Delft RST/Luminescence Materials); van der Knijff, I.C. (TU Delft Optical Technologies); de Wit, A.V. (Student TU Delft); Voet, B. (Student TU Delft); Woudstra, T. (Student TU Delft); Khanin, V. (TU Delft RST/Luminescence Materials); Dorenbos, P. (TU Delft RST/Luminescence Materials); van der Kolk, E. (TU Delft RST/Luminescence Materials)","","2021","The prospect of using Tm2+-doped halides for luminescence solar concentrators (LSCs) requires a thorough understanding of the temperature dependent Tm2+ excited states dynamics that determines the internal quantum efficiency (QE) and thereby the efficiency of the LSC. In this study we investigated the dynamics in CaX2:Tm2+ (X = Cl, Br, I) by temperature- and time-resolved measurements. At 20 K up to four distinct Tm2+ emissions can be observed. Most of these emissions undergo quenching via multi-phonon relaxation below 100 K. At higher temperatures, only the lowest energy 5d–4f emission and the 4f–4f emission remain. Fitting a numerical rate equation model to the data shows that the subsequent quenching of the 5d–4f emission is likely to occur initially via multi-phonon relaxation, whereas at higher temperatures additional quenching via interband crossing becomes thermally activated. At room temperature only the 4f–4f emission remains and the related QE becomes close to 30%. Possible reasons for the quantum efficiency not reaching 100% are provided.","CaCl:Tm CaBr:Tm CaI:Tm+; Luminescence quenching; Photoluminescence; Rate equations modelling; Tm doped halides; Tm excited states dynamics","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:864ea1df-c2f9-4013-9e36-1bbcb2ca7871","http://resolver.tudelft.nl/uuid:864ea1df-c2f9-4013-9e36-1bbcb2ca7871","The role of Yb2+ as a scintillation sensitiser in the near-infrared scintillator CsBa2I5:Sm2+","van Aarle, C. (TU Delft RST/Luminescence Materials); Krämer, Karl W. (University of Bern); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2021","The feasiblity of using Yb2+ as a scintillation sensitiser for CsBa2I5:Sm2+ near-infrared scintillators has been assessed. CsBa2I5 samples with concentrations ranging from 0.3% to 2% Yb2+ and 0–1% Sm2+ have been studied. The scintillation properties have been determined and the dynamics of the scintillation mechanism have been studied through photoluminescence measurements. Radiationless energy transfer between Yb2+ ions plays a key role in increasing the ratio between the spin-forbidden and spin-allowed emission with increasing Yb2+ concentration in samples where Yb2+ is the only dopant. In samples co-doped with Sm2+, the Yb2+ 4f13[F27/2]5d1[LS] and 4f13[F27/2]5d1[HS] states both serve as donor states for radiationless energy transfer to Sm2+ with a rate of energy transfer that is inversely proportional to the luminescence lifetime the respective donor states. At a Sm2+ concentration of 1%, 85% of the Yb2+ excitations are transferred to Sm2+ through radiationless energy transfer. Almost all of the remaining Yb2+ emission is reabsorbed by Sm2+, resulting in nearly complete energy transfer.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:96f2b612-727c-4668-a4bd-86b397d7934b","http://resolver.tudelft.nl/uuid:96f2b612-727c-4668-a4bd-86b397d7934b","Superconducting nanowire single-photon detectors: A perspective on evolution, state-of-the-art, future developments, and applications","Esmaeil Zadeh, I.Z. (TU Delft ImPhys/Optics); Chang, J. (TU Delft ImPhys/Optics); Los, Johannes W.N. (Single Quantum); Gyger, Samuel (KTH Royal Institute of Technology); Elshaari, Ali W. (KTH Royal Institute of Technology); Steinhauer, Stephan (KTH Royal Institute of Technology); Dorenbos, S.N. (Single Quantum); Zwiller, Val (Single Quantum; KTH Royal Institute of Technology)","","2021","Two decades after their demonstration, superconducting nanowire single-photon detectors (SNSPDs) have become indispensable tools for quantum photonics as well as for many other photon-starved applications. This invention has not only led to a burgeoning academic field with a wide range of applications but also triggered industrial efforts. Current state-of-the-art SNSPDs combine near-unity detection efficiency over a wide spectral range, low dark counts, short dead times, and picosecond time resolution. The present perspective discusses important milestones and progress of SNSPDs research, emerging applications, and future challenges and gives an outlook on technological developments required to bring SNSPDs to the next level: a photon-counting, fast time-tagging imaging, and multi-pixel technology that is also compatible with quantum photonic integrated circuits.","","en","journal article","","","","","","","","","","","ImPhys/Optics","","",""
"uuid:8e1c11fc-1eba-4c57-a4d7-3af2a633a35a","http://resolver.tudelft.nl/uuid:8e1c11fc-1eba-4c57-a4d7-3af2a633a35a","Photoluminescence and excited states dynamics of Tm2+-doped CsCa(Cl/Br)3 and CsCa(Br/I)3 perovskites","Plokker, M.P. (TU Delft RST/Luminescence Materials); Biner, D. A. (University of Bern); Dusoswa, N. (TU Delft ChemE/O&O groep); Dorenbos, P. (TU Delft RST/Luminescence Materials); Krämer, K. W. (University of Bern); van der Kolk, E. (TU Delft RST/Luminescence Materials)","","2021","In this study, we systematically vary the Cl/Br and Br/I ratios in CsCaX3:Tm2+ (X = Cl, Br, I) and hereby gradually shift the positions of the Tm2+ 4f125d1-levels as relative to the two 4f13 levels. At low temperatures up to five distinct Tm2+ 4f125d1→4f13 emissions and the 4f13→4f13 emission can be observed. As the temperature increases, most of the 4f125d1→4f13 emissions undergo quenching via multi-phonon relaxation (MPR) and at room temperature only the lowest energy 4f125d1→4f13 and the 4f13→4f13 emission remains. For all compositions a 4f13→4f13 risetime phenomenon is then observed whose duration matches the 4f125d1→4f13 decay time. It shows the feeding of the 4f13 state after 4f125d1 excitation. Surprisingly, the feeding time becomes longer from Cl→Br→I, while the related 4f125d1-4f13 energy gap becomes smaller. The temperature dependence of the 4f125d1→4f13 and 4f13→4f13 emission intensity shows a anticorrelation as earlier observed in other systems and confirms that the feeding process is thermally stimulated. However, the thermally stimulated activation energies that control the feeding process, increase from Cl→Br→I despite our observation that the 4f125d1-4f13 energy gap becomes smaller. An analysis reveals that the unexpected behaviour in risetime and activation energy, as a function of composition, cannot be explained by 4f125d1→4f13 feeding via interband crossing, but more likely via MPR where the electron–phonon coupling strength decreases from Cl→Br→I. No strong relation was found between composition and the quantum efficiency (QE) of the 4f13→4f13 emission, due to the presence of fluctuations that are likely caused by intrinsic differences in sample quality. Nevertheless, a 4f13→4f13 QE of up to 70% has been observed and the materials can therefore be used in luminescence solar concentrators.","CsCaBr3:Tm; CsCaCl3:Tm; CsCaI3:Tm; Halide solid solutions with Tm; Photoluminescence; Tm doped halides; Tm excited states dynamics; OA-Fund TU Delft","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:ca31e188-10d5-48dc-ac1e-dd6ad124338a","http://resolver.tudelft.nl/uuid:ca31e188-10d5-48dc-ac1e-dd6ad124338a","Proceedings of SPIE: Wavelength-resolved Purcell enhancement of PbS/CdS quantum dots measured on a chip-based platform","Elsinger, Lukas (Universiteit Gent); Gourgues, R.B.M. (Single Quantum); Esmaeil Zadeh, I.Z. (TU Delft ImPhys/Optics); Maes, Jorick (Universiteit Gent); Guardiani, A. (Single Quantum); Bulgarini, G. (Single Quantum); Pereira, S.F. (TU Delft ImPhys/Optics); Dorenbos, S.N. (Single Quantum); Zwiller, Val (KTH Royal Institute of Technology)","Adibi, Ali (editor); Lin, Shawn-Yu (editor); Scherer, Axel (editor)","2020","Future quantum optical networks will require an integrated solution to multiplex suitable sources and detectors on a low-loss platform. Here we combined superconducting single-photon detectors with colloidal PbS/CdS quantum dots (QDs) and low-loss silicon nitride passive photonic components to show their combined operation at cryogenic temperatures. Using a planar concave grating spectrometer, we performed wavelength-resolved measurements of the photoluminescence decay of QDs, which were deterministically placed in the gap of plasmonic antennas, in order to improve their emission rate. We observed a Purcell enhancement matching the antenna simulations, with a concurrent increase of the count rate on the superconducting detectors.","Colloidal quantum dots; Photonic integration; Plasmonic antennas; Silicon nitride; Superconducting nanowire single-photon detectors","en","conference paper","SPIE","","","","","","","","","","ImPhys/Optics","","",""
"uuid:a3aca28c-9af9-44b6-8f19-d6640df5973b","http://resolver.tudelft.nl/uuid:a3aca28c-9af9-44b6-8f19-d6640df5973b","Persistent luminescence excitation spectroscopy of BaAl2O4:Eu2+,Dy3+","Malkamäki, Marja (University of Turku); bos, A.J.J. (TU Delft RST/Luminescence Materials); Dorenbos, P. (TU Delft RST/Luminescence Materials); Lastusaari, Mika (University of Turku); Rodrigues, Lucas C.V. (Universidade de São Paulo); Swart, Hendrik C. (University of the Free State); Hölsä, Jorma (University of Turku; Universidade de São Paulo; University of the Free State; Polish Academy of Sciences)","","2020","BaAl2O4:Eu2+,Dy3+ is related, both by structure and luminescence, to one of the best persistent luminescent phosphors, SrAl2O4:Eu2+,Dy3+. At room temperature (RT), the green persistent emission of BaAl2O4:Eu2+,Dy3+ remains visible for hours after ceasing irradiation. Similar to SrAl2O4, BaAl2O4 with hexagonal P63 structure, has two M2+ sites, but, limited optical activity from the 2nd site is observed in the emission of BaAl2O4:Eu2+,Dy3+ - even at 77 K. Using combined approach of photoluminescence, thermoluminescence (TL), and persistent (excitation) luminescence measurements, the origin and properties of persistent luminescence of BaAl2O4:Eu2+,Dy3+ were studied in detail. Ultraviolet (UV) excited and persistent emission are identical and no contribution from the Eu2+ in the high-symmetry Ba site was observed. TL excitation spectra clarified the unstructured conventional excitation spectrum; now it is evident that defects or the Dy3+ co-dopant do not contribute to persistent luminescence via direct energy absorption. Mechanisms for persistent luminescence should thus be revised.","BaAlO; Eu+Dy co-doping; Excitation; Persistent luminescence; Thermoluminescence","en","journal article","","","","","","Accepted Author Manuscript","","2022-04-04","","","RST/Luminescence Materials","","",""
"uuid:d9f97f6c-5ccf-44d2-a3b1-84d3cb228b23","http://resolver.tudelft.nl/uuid:d9f97f6c-5ccf-44d2-a3b1-84d3cb228b23","Towards information storage by designing both electron and hole detrapping processes in bismuth and lanthanide-doped LiRE(Si,Ge)O4 (RE = Y, Lu) with high charge carrier storage capacity","Lyu, T. (TU Delft RST/Luminescence Materials); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2020","Guided by vacuum referred binding energy (VRBE) diagrams, both the trapping and detrapping processes of electrons and holes are explored in the bismuth and lanthanide-doped LiRE(Si,Ge)O4 (RE = Y, Lu) family of compounds. The Tm3+ electron trap has been combined with the deep hole traps of Ln3+ (Ln = Ce, Tb, or Pr) or Bi3+ in LiLuSiO4. During the thermoluminescence readout, the electrons released from Tm2+ recombine with holes at Ln4+ and Bi4+ to produce typical Ln3+ 4f-4f or 5d-4f emission and Bi3+ A-band emission. The electron trap depth of lanthanide ions can be tuned by the choice of Ln3+ (Ln = Tm or Sm), and for fixed pair of Ln3+ and/or Bi3+ dopants like in LiLu1−xYxSiO4:0.01Ce3+,0.01Ln3+ and LiLu1−xYxSiO4:0.01Bi3+,0.01Sm3+ solid solutions, by adjusting x, resulting in the engineering of the VRBE at the conduction band bottom. The thermoluminescence (TL) intensity of the optimized LiLu0.5Y0.5SiO4:0.01Ce3+, 0.005Sm3+ is about 8.5 times higher than that of the commercial X-ray BaFBr(I):Eu2+ storage phosphor. By combining deep Eu3+ or Bi3+ electron traps with Ln3+ (Ln = Tb or Pr) or Bi3+, Ln3+ and Bi3+ appear to act as less deep hole capturing centres in LiLuSiO4. Here the recombination is achieved through hole liberation rather than the more commonly reported electron liberation. The holes are released from Ln4+ and Bi4+ to recombine with electrons at Eu2+ or Bi2+ to give characteristic Eu3+ 4f-4f and Bi3+ A-band emissions. The tailoring of Ln3+ and Bi3+ hole trap depths by crystal composition modulation is discussed in LiLu1−xYxSiO4 and LiLu0.25Y0.75Si1−yGeyO4:0.01Bi3+ solid solutions. The TL intensity of the optimized LiLu0.25Y0.75SiO4:0.01Bi3+ is ~4.4 times higher than that of the commercial BaFBr(I):Eu2+. Proof-of-concept information storage will be demonstrated with X-ray or UV-light charged LiLu0.5Y0.5SiO4:0.01Ce3+,0.01Sm3+ and LiLu0.25Y0.75SiO4:0.01Bi3+ phosphors dispersed in silicone gel imaging plates.","Bismuth; Energy conversion; Energy storage; Hole liberation; Trap engineering","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:10f46259-cf5b-4970-97ea-884b3234c8fe","http://resolver.tudelft.nl/uuid:10f46259-cf5b-4970-97ea-884b3234c8fe","Vacuum-Referred Binding Energies of Bismuth and Lanthanide Levels in ARE(Si,Ge)O4 (A = Li, Na; RE = Y, Lu): Toward Designing Charge-Carrier-Trapping Processes for Energy Storage","Lyu, T. (TU Delft RST/Luminescence Materials); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2020","Developing a feasible design principle for solid-state materials for persistent luminescence and storage phosphors with high charge carrier storage capacity remains a crucial challenge. Here we report a methodology for such rational design via vacuum referred binding energy (VRBE) diagram aided band structure engineering and crystal synthesis optimization. The ARE(Si,Ge)O4 (A = Li, Na; RE = Y, Lu) crystal system was selected as a model example. Low-temperature (10 K) photoluminescence excitation and emission spectra of bismuth- and lanthanide-doped ARE(Si,Ge)O4 system were first systematically studied, and the corresponding VRBE schemes were then established. Guided by these VRBE schemes, Bi3+ afterglow and storage phosphor properties were explored in NaLu1-xYxGeO4. By combining Bi3+ with Bi3+ itself or Eu3+, Bi3+ appears to act as a deep hole-trapping center, while Bi3+ and Eu3+ act as less-deep electron traps. Trap depth tunable afterglow and storage were realized in NaLu1-xYxGeO4:0.01Bi3+ and NaLu1-xYxGeO4:0.01Bi3+,0.001Eu3+ by adjusting x, leading to conduction band engineering. More than 28 h of persistent luminescence of Bi3+ was measurable in NaYGeO4:0.01Bi3+ due to electron release from Bi2+ and recombination with a hole at Bi4+. The charge carrier storage capacity in NaYGeO4:0.01Bi3+ was discovered to increase ∼7 times via optimizing synthesis condition at 1200 °C during 24 h. The thermoluminescence (TL) intensity of the optimized NaYGeO4:0.001Bi3+ and NaYGeO4:0.01Bi3+,0.001Eu3+ is ∼3, and ∼7 times higher than the TL of the state-of-the-art X-ray storage phosphor BaFBr(I):Eu. Proof-of-concept color tuning for anti-counterfeiting application was demonstrated by combining the discovered and optimized NaYGeO4:0.01Bi3+ afterglow phosphor with perovskite CsPbBr3 and CdSe quantum dots. Information storage application was demonstrated by UV-light- or X-ray-charged NaYGeO4:0.01Bi3+,0.001Eu3+ phosphor dispersed in a silicone gel imaging film. This work not only reports excellent storage phosphors but more importantly provides a design principle that can initiate more exploration of afterglow and storage phosphors in a designed way through combining VRBE-scheme-guided band structure engineering and crystal synthesis optimization.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:8b849587-dddf-4cf1-8c73-86ad5cf703c3","http://resolver.tudelft.nl/uuid:8b849587-dddf-4cf1-8c73-86ad5cf703c3","Engineering near-infrared emitting scintillators with efficient Eu2+ → Sm2+ energy transfer","Wolszczak, W.W. (TU Delft RST/Luminescence Materials); Krämer, K. W. (University of Bern); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2020","Recently, we proposed a concept for a new class of near infrared (NIR) scintillators by employing efficient Eu2+ → Sm2+ energy transfer. In this article we investigate the optical spectroscopy of Sm2+ in BaBrI, CsSrI3, and CsBa2I5 halide hosts. A criterion was derived for fast Sm2+ 5d → 4f emission and a list of new potential NIR scintillators is proposed.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:0c9ca540-037c-4f20-93b0-6ced938a3278","http://resolver.tudelft.nl/uuid:0c9ca540-037c-4f20-93b0-6ced938a3278","Efficient Single-Photon Detection with 7.7 ps Time Resolution for Photon-Correlation Measurements","Esmaeil Zadeh, I.Z. (TU Delft ImPhys/Optics; Single Quantum); Chang, J. (TU Delft ImPhys/Optics); Van Staaden, Yuri J. (Student TU Delft); Swens, Jeroen P.E. (Student TU Delft); Dobrovolskiy, S.M. (Single Quantum); Schaart, D.R. (TU Delft RST/Medical Physics & Technology); Pereira, S.F. (TU Delft ImPhys/Optics); Zwiller, Val (Single Quantum; KTH Royal Institute of Technology); Dorenbos, S.N. (Single Quantum)","","2020","A broad range of scientific and industrial disciplines require precise optical measurements at very low light levels. Single-photon detectors combining high efficiency and high time resolution are pivotal in such experiments. By using relatively thick films of NbTiN (8-11 nm) and improving the pattern fidelity of the nanostructure of the superconducting nanowire single-photon detectors (SNSPD), we fabricated devices demonstrating superior performance over all previously reported detectors in the combination of efficiency and time resolution. Our findings prove that small variations in the nanowire width, in the order of a few nanometers, can lead to a significant penalty on their temporal response. Addressing these issues, we consistently achieved high time resolution (best device 7.7 ps, other devices a10-16 ps) simultaneously with high system detection efficiencies (80-90%) in the wavelength range of 780-1000 nm, as well as in the telecom bands (1310-1550 nm). The use of thicker films allowed us to fabricate large-area multipixel devices with homogeneous pixel performance. We first fabricated and characterized a 100 × 100 μm2 16-pixel detector and showed there was little variation among individual pixels. Additionally, to showcase the power of our platform, we fabricated and characterized 4-pixel multimode fiber-coupled detectors and carried out photon-correlation experiments on a nanowire quantum dot resulting in g2(0) values lower than 0.04. The multipixel detectors alleviate the need for beamsplitters and can be used for higher order correlations with promising prospects not only in the field of quantum optics, but also in bioimaging applications, such as fluorescence microscopy and positron emission tomography.","high time resolution; multipixel detectors; photon correlation; quantum optics; superconducting nanowire single-photon detector","en","journal article","","","","","","","","","","","ImPhys/Optics","","",""
"uuid:18589e31-422e-452f-972f-3e010aa1eb6b","http://resolver.tudelft.nl/uuid:18589e31-422e-452f-972f-3e010aa1eb6b","Machine learning 5d-level centroid shift of Ce3+inorganic phosphors","Zhuo, Ya (University of Houston); Hariyani, Shruti (University of Houston); You, Shihai (Xiamen University; University of Houston); Dorenbos, P. (TU Delft RST/Luminescence Materials); Brgoch, Jakoah (University of Houston)","","2020","Information on the 5d level centroid shift (ϵc) of rare-earth ions is critical for determining the chemical shift and the Coulomb repulsion parameter as well as predicting the luminescence and thermal response of rare-earth substituted inorganic phosphors. The magnitude of ϵc depends on the binding strength between the rare-earth ion and its coordinating ligands, which is difficult to quantify a priori and makes phosphor design particularly challenging. In this work, a tree-based ensemble learning algorithm employing extreme gradient boosting is trained to predict ϵc by analyzing the optical properties of 160 Ce3+ substituted inorganic phosphors. The experimentally measured ϵc of these compounds was featurized using the materials' relative permittivity (ϵr), average electronegativity, average polarizability, and local geometry. Because the number of reported ϵr values is limited, it was necessary to utilize a predicted relative permittivity (ϵr,SVR) obtained from a support vector regressor trained on data from ∼2800 density functional theory calculations. The remaining features were compiled from open-source databases and by analyzing the rare-earth coordination environment from each Crystallographic Information File. The resulting ensemble model could reliably estimate ϵc and provide insight into the optical properties of Ce3+-activated inorganic phosphors.","","en","journal article","","","","","","Accepted Author Manuscript","","2021-07-02","","","RST/Luminescence Materials","","",""
"uuid:d75bbd1f-1072-41b9-986a-772806f83735","http://resolver.tudelft.nl/uuid:d75bbd1f-1072-41b9-986a-772806f83735","Site Occupancies, VUV-UV-vis Photoluminescence, and X-ray Radioluminescence of Eu2+-Doped RbBaPO4","Zhou, Rongfu (Sun Yat-sen University); Ma, Fengkai (Sun Yat-sen University); Su, Fang (Sun Yat-sen University); Ou, Yiyi (Sun Yat-sen University); Qi, Zeming (University of Science and Technology of China); Zhang, Jianhui (Sun Yat-sen University); Huang, Yan (Institute of High Energy Physics Chinese Academy of Science); Dorenbos, P. (TU Delft RST/Luminescence Materials); Liang, Hongbin (Sun Yat-sen University)","","2020","RbBaPO4:Eu2+ phosphors have been prepared by a high-temperature solid-state reaction method, and the structure was determined by Rietveld refinement based on powder X-ray diffraction (P-XRD) data. Their VUV-UV-vis photoluminescence properties are systematically investigated with three objectives: (1) based on low-temperature spectra, we clarify the site occupancies of Eu2+, and demonstrate that the doublet emission bands at ∼406 and ∼431 nm originate from Eu2+ in Ba2+ [Eu2+(I)] and Rb+ [Eu2+(II)] sites, respectively; (2) an electron-vibrational interaction (EVI) analysis is conducted to estimate the Huang-Rhys factors, the zero-phonon lines (ZPLs) and the Stokes shifts of Eu2+ in Rb+ and Ba2+ sites; (3) the studies on luminescence decay of Eu2+(I) reveal that dipole-dipole interaction is mainly responsible for the energy transfer from Eu2+(I) to Eu2+(II), and the energy migration between Eu2+(I) is weak. Finally, the X-ray excited luminescence (XEL) spectrum indicates that the light yield of the sample RbBa0.995Eu0.005PO4 is ∼17700 ph/MeV, showing its potential application in X-ray detecting.","","en","journal article","","","","","","Accepted Author Manuscript","","2021-11-12","","","RST/Luminescence Materials","","",""
"uuid:576a2972-81fb-4690-afbd-df71720b03fe","http://resolver.tudelft.nl/uuid:576a2972-81fb-4690-afbd-df71720b03fe","[INVITED] Improved parameters for the lanthanide 4fq and 4fq−15d curves in HRBE and VRBE schemes that takes the nephelauxetic effect into account","Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2020","In first approximation the binding of an electron in lanthanide 4fq ground states changes with q in a characteristic zigzag shape that is independent on type of compound. Those shapes have been parameterized in past publications and are used to construct host referred binding energy (HRBE) or vacuum referred binding energy (VRBE) schemes showing the lanthanide 4fq level locations with respect to the host valence bands or to the vacuum level. There is experimental evidence for a slight compound dependence, and a model explaining that has appeared recently (Dorenbos, 2019). This all implies that the parameters for constructing HRBE and VRBE schemes need to be revised and a compound dependence needs to be introduced as a second order approximation. In this work the improved parameters are derived from the 3rd and 4th ionization potentials of the lanthanide atoms. In compounds, as explained by the chemical shift model, the free ion binding energy curves undergo an upward shift due to Coulomb repulsion from anion ligands and they undergo a tilt due to the lanthanide contraction. In this work we will use the nephelauxetic parameter β to add a compound dependence. Its main effect is an increased binding in the 4fq ground states for the lanthanides from the right hand branch (q > 7) of the zigzag curves. The same applies for the 4fq−15d excited states with (q−1)>7. Collected spectroscopic data on divalent and trivalent lanthanides from more than 1000 different compounds have been analyzed to arrive at the proposed revised parameters for the 4fq and 4fq−15d binding energy curves.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:8179972e-01b6-44de-9823-26f43543388e","http://resolver.tudelft.nl/uuid:8179972e-01b6-44de-9823-26f43543388e","Superconducting nanowire single photon detectors operating at temperature from 4 to 7 K","Gourgues, R.B.M. (Single Quantum); Los, J.W.N. (Single Quantum); Zichi, Julien (KTH Royal Institute of Technology); Chang, J. (TU Delft ImPhys/Optics); Kalhor, N. (Single Quantum); Bulgarini, G. (Single Quantum); Dorenbos, S.N. (Single Quantum); Zwiller, Val (KTH Royal Institute of Technology); Esmaeil Zadeh, I.Z. (TU Delft ImPhys/Optics)","","2019","We experimentally investigate the performance of NbTiN superconducting nanowire single photon detectors above the base temperature of a conventional Gifford-McMahon cryocooler (2.5 K). By tailoring design and thickness (8 - 13 nm) of the detectors, high performance, high operating temperature, single-photon detection from the visible to telecom wavelengths are demonstrated. At 4.3 K, a detection efficiency of 82 % at 785 nm wavelength and a timing jitter of 30 ± 0.3 ps are achieved. In addition, for 1550 nm and similar operating temperature we measured a detection efficiency as high as 64 %. Finally, we show that at temperatures up to 7 K, unity internal efficiency is maintained for the visible spectrum. Our work is particularly important to allow for the large scale implementation of superconducting single photon detectors in combination with heat sources such as free-space optical windows, cryogenic electronics, microwave sources and active optical components for complex quantum optical experiments and bio-imaging.","","en","journal article","","","","","","","","","","","ImPhys/Optics","","",""
"uuid:9f54a11d-fa39-469d-b9eb-b1e3c7f0c061","http://resolver.tudelft.nl/uuid:9f54a11d-fa39-469d-b9eb-b1e3c7f0c061","Synthesis optimization and charge carrier transfer mechanism in LiLuSiO4:Ce, Tm storage phosphor","Dobrowolska, Anna (External organisation); bos, A.J.J. (TU Delft RST/Fundamental Aspects of Materials and Energy; TU Delft RST/Luminescence Materials); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2019","LiLuSiO4:Ce and LiLuSiO4:Ce, Tm show very efficient charge carrier storage properties upon beta irradiation after samples have received treatment in vacuum. They outperform the commercial storage phosphor BaFBr(I):Eu2+ in many aspects. The influence of the synthesis conditions, Ce and Tm concentration, nonstoichiometry and codoping with Ca, Hf, Al and Ge are reported. Based on the results of the synthesis optimization, thermoluminescence (TL) emission and TL excitation spectra a mechanism of charge carrier transfer, storage, and recombination during irradiation and thermal or optical readout is proposed.","Cerium; Charge transfer; Storage phosphors; Thermoluminescence; Thulium","en","journal article","","","","","","Accepted Author Manuscript","","2021-08-02","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:0d532d08-6ac5-4b9d-80f7-5ffc339dd147","http://resolver.tudelft.nl/uuid:0d532d08-6ac5-4b9d-80f7-5ffc339dd147","The nephelauxetic effect on the electron binding energy in the 4fq ground state of lanthanides in compounds","Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2019","In the construction of a vacuum referred binding energy (VRBE) diagram with the lanthanide 4fq ground states, always a compound independent variation with the number q= 1 to 14 is assumed. Experimental data from thermo-luminescence, intervalence charge transfer bands, and thermo-bleaching studies provide first indications that a minor compound dependence does exist. To explain its origin we will first apply Jørgensen spin pairing theory to reproduce the VRBE in the ground states of the free di- and trivalent lanthanide ions which is equivalent to the 3rd and 4th ionization potentials of the lanthanide atoms. By combining experimental data and calculated trends therein, the relevant Racah E1, Racah E3, and spin orbit coupling ζff parameters for all di-, tri-, and tetravalent free ion lanthanides are derived. Using that as input for the spin pairing theory, the characteristic zigzag shapes in VRBE as function of q, as derived from ionization potentials, are nicely reproduced. Because of the nephelauxetic effect the parameter values are lowered when lanthanides are in compounds. How that reduction affects the VRBE curves will be treated in this work.","","en","journal article","","","","","","Accepted Author Manuscript","","2021-06-15","","","RST/Luminescence Materials","","",""
"uuid:a21b2590-715a-414d-89b2-08a575738a6b","http://resolver.tudelft.nl/uuid:a21b2590-715a-414d-89b2-08a575738a6b","The Pr 3+ and Tb 3+ ground state locations in compounds obtained from thermoluminescence and intervalence charge transfer studies","Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy; TU Delft RST/Luminescence Materials)","","2019","The location of the lanthanide ground states with respect to the host valence band or to the vacuum level always follow characteristic zigzag patterns with the number of electrons q in the 4f orbital. The patterns that are used today evolved over the years by combining experimental data from different techniques, and they are in first approximation independent on the type of compound. Here we will demonstrate that the ground state locations for Pr 3+ and Tb 3+ in the currently used pattern for trivalent lanthanides appear, when inspected on the ± 0.1 eV accuracy level, not consistent with two independent sets of experimental data. One set is from data on the intervalence charge transfer (IVCT) from Pr 3+ and Tb 3+ to the conduction band (CB) observed in luminescence excitation spectra. The other set is from the release of holes from Pr 4+ and Tb 4+ to the valence band observed in thermoluminescence (TL). In addition to the inconsistency, TL based evidence for a slight compound dependence in the characteristic zigzag patterns is found.","Binding energy; Electronic structure; Intervalence charge transfer; Lanthanide levels; Thermoluminescence","en","journal article","","","","","","Accepted Author Manuscript","","2021-03-30","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:976a1b95-219c-47ca-9bfe-4418b65075a7","http://resolver.tudelft.nl/uuid:976a1b95-219c-47ca-9bfe-4418b65075a7","How to predict the location of the defect levels induced by 3d transition metal ions at octahedral sites of aluminate phosphors","Qu, Bingyan (Hefei University of Technology); Zhou, Rulong (Hefei University of Technology); Wang, L. (TU Delft RST/Fundamental Aspects of Materials and Energy; Hefei University of Technology); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2019","How the 3d transition metal (TM) ions induce defect levels in wide band gap compounds and how these defect levels evolve from compound to compound is very important in understanding and predicting the luminescent properties of TM activated phosphors. This issue is discussed by studying the ground state 3dn level locations of the TM impurity ions (Sc-Zn) incorporated at the octahedral sites of many oxides. These ground state 3dn level locations are obtained by collecting the CT bands from the literature of the past 50 years and also by first-principles calculations. By taking the vacuum level as the reference, we scaled all the locations of the TM ion in 3+ and 2+ states and constructed a zig-zag-curve scheme in α-Al2O3 through connecting the 3dn ground state energies of Sc to Zn. The scheme can be extended to other aluminates easily and so offers a first estimate on where TM levels are located in compounds without complicated theoretical calculations. The estimate can be improved to a higher accuracy if the position of the valence band is known. Our work provides new insights for understanding the luminescent behavior of 3d-TM doped phosphors and may aid in developing 3d ion doped functional materials further.","","en","journal article","","","","","","Accepted Author Manuscript","","2019-11-23","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:8ab28b0f-b1a8-464e-be83-b9ab6f116b1e","http://resolver.tudelft.nl/uuid:8ab28b0f-b1a8-464e-be83-b9ab6f116b1e","Multimode-fiber-coupled superconducting nanowire single-photon detectors with high detection efficiency and time resolution","Chang, J. (TU Delft ImPhys/Optics); Esmaeil Zadeh, I.Z. (TU Delft ImPhys/Optics); Los, Johannes W.N. (Single Quantum); Zichi, Julien (KTH Royal Institute of Technology); Fognini, Andreas (Single Quantum); Gevers, Monique (Single Quantum); Dorenbos, Sander (Single Quantum); Pereira, S.F. (TU Delft ImPhys/Optics); Urbach, Paul (TU Delft ImPhys/Optics); Zwiller, Val (KTH Royal Institute of Technology)","","2019","In the past decade, superconducting nanowire single-photon detectors (SNSPDs) have gradually become an indispensable part of any demanding quantum optics experiment. Until now, most SNSPDs have been coupled to single-mode fibers. SNSPDs coupled to multimode fibers have shown promising efficiencies but have yet to achieve high time resolution. For a number of applications ranging from quantum nano-photonics to bio-optics, high efficiency and high time resolution are desired at the same time. In this paper, we demonstrate the role of polarization on the efficiency of multimode-fiber-coupled detectors and fabricated high-performance 20 µm, 25 µm, and 50 µm diameter detectors targeted for visible, near-infrared, and telecom wavelengths. A custom-built setup was used to simulate realistic experiments with randomized modes in the fiber. We achieved over 80% system efficiency and <20 ps timing jitter for 20 µm SNSPDs. Also, we realized 70% system efficiency and <20 ps timing jitter for 50 µm SNSPDs. The high-efficiency multimode-fiber-coupled SNSPDs with unparalleled time resolution will benefit various quantum optics experiments and applications in the future.","","en","journal article","","","","","","","","","","","ImPhys/Optics","","",""
"uuid:ec62f032-a892-4754-83f3-e26efa05e3ae","http://resolver.tudelft.nl/uuid:ec62f032-a892-4754-83f3-e26efa05e3ae","The quest for high resolution γ-ray scintillators","Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2019","There are many properties of scintillators that are of importance for application. One property is the energy resolution for the detection of γ-rays, and during past 20 years we witnessed enormous progress. The state of the art resolution for the detection of 662 keV γ photons was 5–6% at the end of the 20th century, and today scintillators with 2.2% resolution are commercially available. This work will provide a review on the development of high resolution chloride, bromide, and iodide based scintillators that occurred since the discovery of the LaCl3:Ce3+ scintillator in 2000. Bandgap engineering and co-doping to eliminate afterglow or to improve proportionality have become new tools in optimizing scintillator performance. At the end of the review the prospects for the development of scintillators with resolution <2% are addressed together with new research strategies that might be required to accomplish that.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:97bf6b5c-caf9-4864-9053-15c4e2a694e8","http://resolver.tudelft.nl/uuid:97bf6b5c-caf9-4864-9053-15c4e2a694e8","Impacts of 5d electron binding energy and electron-phonon coupling on luminescence of Ce 3+ in Li 6 Y(BO 3 ) 3","Ou, Yiyi (Sun Yat-sen University); Zhou, Weijie (Sun Yat-sen University); Hou, Dejian (Hanshan Normal University, Chaozhou); Brik, Mikhail G. (Chongqing University of Posts and Telecommunications; University of Tartu; Jan Długosz University); Dorenbos, P. (TU Delft RST/Luminescence Materials); Huang, Yan (Institute of High Energy Physics Chinese Academy of Science); Liang, Hongbin (Sun Yat-sen University)","","2019","In this work, the crystal structure and electronic structure as well as the synchrotron radiation vacuum ultraviolet-ultraviolet-visible (VUV-UV-vis) luminescence properties of Li 6 Y(BO 3 ) 3 (LYBO):Ce 3+ phosphors were investigated in detail. The Rietveld refinement and DFT calculation reveal the P2 1 /c monoclinic crystal phase and the direct band gap of the LYBO compound, respectively. Only one kind of Ce 3+ 4f-5d transition is resolved in terms of the low temperature VUV-UV excitation, UV-vis emission spectra and luminescence decay curves. Furthermore, by constructing the vacuum referred binding energy (VRBE) scheme and applying the frequency-degenerate vibrational model, the impacts of 5d electron binding energy and electron-phonon coupling on luminescence of Ce 3+ in LYBO are analysed. The results show that the Ce 3+ emission in LYBO possesses a moderate intrinsic thermal stability. With the increase in concentration, the thermal stability of the emission gets worse due to the possible thermally-activated concentration quenching. In addition, the simulation of Ce 3+ emission profile at low temperature reveals that the 4f-5d electronic transitions of Ce 3+ ions can be treated to couple with one frequency-degenerate vibrational mode having the effective phonon energy of ∼257 cm −1 with the corresponding Huang-Rhys parameter of ∼6, which indicates a strong electron-phonon interaction of Ce 3+ luminescence in the Li 6 Y(BO 3 ) 3 host. Finally, the X-ray excited luminescence spectrum of the LYBO:5%Ce 3+ phosphor is measured to check the potential scintillator applications.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:bca4eab0-e95f-476e-ae99-faa826c67a22","http://resolver.tudelft.nl/uuid:bca4eab0-e95f-476e-ae99-faa826c67a22","Controlled integration of selected detectors and emitters in photonic integrated circuits","Gourgues, R.B.M. (TU Delft QN/Afdelingsbureau); Esmaeil Zadeh, I.Z. (TU Delft ImPhys/Optics); Elshaari, A.W.A. (KTH Royal Institute of Technology); Bulgarini, G. (TU Delft QN/Afdelingsbureau); Los, J.W.N. (TU Delft QN/Afdelingsbureau); Zichi, Julien (KTH Royal Institute of Technology); Dalacu, Dan (National Research Council Canada); Poole, Philip J. (National Research Council Canada); Dorenbos, S.N. (TU Delft QN/Afdelingsbureau); Zwiller, And V.A.L. (KTH Royal Institute of Technology)","","2019","Integration of superconducting nanowire single-photon detectors and quantum sources with photonic waveguides is crucial for realizing advanced quantum integrated circuits. However, scalability is hindered by stringent requirements on high-performance detectors. Here we overcome the yield limitation by controlled coupling of photonic channels to pre-selected detectors based on measuring critical current, timing resolution, and detection efficiency. As a proof of concept of our approach, we demonstrate a hybrid on-chip full-transceiver consisting of a deterministically integrated detector coupled to a selected nanowire quantum dot through a filtering circuit made of a silicon nitride waveguide and a ring resonator filter, delivering 100 dB suppression of the excitation laser. In addition, we perform extensive testing of the detectors before and after integration in the photonic circuit and show that the high performance of the superconducting nanowire detectors, including timing jitter down to 23 ± 3 ps, is maintained. Our approach is fully compatible with wafer-level automated testing in a cleanroom environment.","","en","journal article","","","","","","","","","","","QN/Afdelingsbureau","","",""
"uuid:4539fd9c-efe6-4326-af15-f590129fea0b","http://resolver.tudelft.nl/uuid:4539fd9c-efe6-4326-af15-f590129fea0b","Converting SrI 2 :Eu 2+ into a near infrared scintillator by Sm 2+ co-doping","Awater, R.H.P. (Student TU Delft); Alekhin, M. (Student TU Delft); Biner, D. A. (University of Bern); Krämer, K.M.B. (University of Bern); Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy; TU Delft RST/Luminescence Materials)","","2019","The luminescence and scintillation properties of SrI 2 single crystals doped with 5% Eu 2+ and 0.05%, 0.2% and 0.5% Sm 2+ are evaluated. X-ray excited and photoluminescence measurements show energy transfer from excited Eu 2+ ions to Sm 2+ ions. At a concentration of 0.5% Sm 2+ , the luminescence consists almost entirely of 740 nm emission from Sm 2+ 5d-4f transitions. Co-doping SrI 2 :5% Eu 2+ with Sm 2+ provides a novel method to bypass the self-absorption problem encountered in large SrI 2 :Eu 2+ crystals and, at the same time, provides a unique near-infrared emitting scintillator with a light yield of approximately 40,000 photons/MeV.","","en","journal article","","","","","","Accepted Author Manuscript","","2021-04-12","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:691980a6-c288-433e-9091-f84dac2b6d96","http://resolver.tudelft.nl/uuid:691980a6-c288-433e-9091-f84dac2b6d96","Designing thermally stimulated 1.06 mu m Nd3+ emission for the second bio-imaging window demonstrated by energy transfer from Bi3+ in La-, Gd-, Y-, and LuPO4","Lyu, T. (TU Delft RST/Luminescence Materials); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2019","We report a general methodology to the rational design of thermally stimulated short-wave infrared (SWIR) luminescence between ∼900 and 1700 nm by a new combination of using efficient energy transfer from Bi 3+ to Nd 3+ and an adjustable hole trap depth via valence band engineering. Predictions from a vacuum referred binding energy (VRBE) diagram are combined with the data from optical spectroscopy and thermoluminescence to show the design concept by using bismuth and lanthanide doped rare earth ortho-phosphates as model examples. Nd 3+ with its characteristic 4 F 3/2 → 4 I j (j = 9/2, 11/2, 13/2) emission in the SWIR range is first selected as the emitting centre. The energy transfer (ET) processes from Bi 3+ or Tb 3+ recombination centres to Nd 3+ are then discussed. Photoluminescence results show that the energy transfer efficiency of Bi 3+ → Nd 3+ appears to be much higher than of Tb 3+ → Nd 3+ . To exploit this ET, thermally stimulated Bi 3+ A-band emission can then be designed by using Bi 3+ as a ∼2.7 eV deep electron trap in YPO 4 . By combining Bi 3+ with Tb 3+ , Pr 3+ , or Bi 3+ itself, the holes trapped at Tb 4+ , Pr 4+ , or Bi 4+ will release earlier than the electrons captured at Bi 2+ . On recombination with Bi 2+ , Bi 3+ in its excited state is formed generating Bi 3+ A-band emission. Due to the ET of Bi 3+ → Nd 3+ 1.06 μm Nd 3+ emission appears in YPO 4 . Herein, the thermally stimulated Nd 3+ SWIR emission is achieved by hole release rather than the more commonly reported electron release. The temperature when thermally stimulated Nd 3+ SWIR emission appears can further be engineered by changing the Tb 3+ or Pr 3+ hole trap depth in Y 1−x Lu x PO 4 by adjusting x. Such valence band engineering approach can also be applied to other compounds like La 1−x Gd x PO 4 and Gd 1−x La x AlO 3 solid solutions. Our work opens the avenue to motivate scientists to explore novel SWIR afterglow phosphors in a design way instead of by trial and error approach.","Afterglow; Bismuth; Energy transfer; Hole release; Valence band engineering","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:454fe294-2f27-49db-ba07-d3167bc5cb78","http://resolver.tudelft.nl/uuid:454fe294-2f27-49db-ba07-d3167bc5cb78","Integration of Colloidal PbS/CdS Quantum Dots with Plasmonic Antennas and Superconducting Detectors on a Silicon Nitride Photonic Platform","Elsinger, Lukas (Universiteit Gent); Gourgues, R.B.M. (Single Quantum); Esmaeil Zadeh, I.Z. (TU Delft ImPhys/Optics); Maes, Jorick (Universiteit Gent); Guardiani, A. (Single Quantum); Bulgarini, G. (Single Quantum); Pereira, S.F. (TU Delft ImPhys/Optics); Dorenbos, S.N. (Single Quantum); Zwiller, V.G. (KTH Royal Institute of Technology)","","2019","Single-photon sources and detectors are indispensable building blocks for integrated quantum photonics, a research field that is seeing ever increasing interest for numerous applications. In this work, we implemented essential components for a quantum key distribution transceiver on a single photonic chip. Plasmonic antennas on top of silicon nitride waveguides provide Purcell enhancement with a concurrent increase of the count rate, speeding up the microsecond radiative lifetime of IR-emitting colloidal PbS/CdS quantum dots (QDs). The use of low-fluorescence silicon nitride, with a waveguide loss smaller than 1 dB/cm, made it possible to implement high extinction ratio optical filters and low insertion loss spectrometers. Waveguide-coupled superconducting nanowire single-photon detectors allow for low time-jitter single-photon detection. To showcase the performance of the components, we demonstrate on-chip lifetime spectroscopy of PbS/CdS QDs. The method developed in this paper is predicted to scale down to single QDs, and newly developed emitters can be readily integrated on the chip-based platform.","Colloidal quantum dots; hybrid integrated photonics; plasmonic antennas; superconducting nanowire single photon detector","en","journal article","","","","","","Accepted Author Manuscript","","2020-07-07","","","ImPhys/Optics","","",""
"uuid:0c159619-c61f-4181-8e19-add5ae5ae7b6","http://resolver.tudelft.nl/uuid:0c159619-c61f-4181-8e19-add5ae5ae7b6","The hole picture as alternative for the common electron picture to describe hole trapping and luminescence quenching","Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy)","","2018","Electronic level schemes with the host valence and conduction band together with the level locations of ground and excited states of defects are used to explain and predict luminescence and carrier trapping phenomena. These schemes are always constructed and interpreted by using the electron picture. In this work the alternative hole picture is presented. Such picture is sometimes used in the field of semi-conductors but hardly ever in the field of wide band gap inorganic compounds. We will focus on the lanthanides, and first show where to draw the hole ground state and excited hole states in our scheme. It leads to up-side-down Dieke diagrams and up-side-down configuration coordinate diagrams but for the rest everything is equivalent to the electron picture. With the hole picture, luminescence quenching via hole ionization to the valence band and hole trapping in defects can be illustrated much more conveniently than with the electron picture. As examples the quenching of the Tb3+ D45 emissions by electron ionization and the quenching of the Eu3+ D05 emissions by hole ionization are compared.","","en","journal article","","","","","","Accepted Author Manuscript","","2020-01-30","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:e90c1739-c097-47ba-9c08-6269d8123409","http://resolver.tudelft.nl/uuid:e90c1739-c097-47ba-9c08-6269d8123409","The dual role of Cr3+ in trapping holes and electrons in lanthanide co-doped GdAlO3 and LaAlO3","Luo, H. (TU Delft RST/Fundamental Aspects of Materials and Energy); Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy)","","2018","Trivalent Nd, Dy, Ho, Er, Tm, Sm and Eu usually act as electron trapping centers in wide band gap compounds, whereas trivalent Ce, Tb and Pr act as hole trapping centers. When a deep electron trap is combined with a shallow hole trap, then during the thermoluminescence glow the hole is released, generating recombination luminescence at the electron trap. However, in the case of a shallow electron trap, the electron will be released to recombine at the hole trapping center. With the knowledge of the location of the lanthanide levels within the band gap, one may engineer the depth of the electron trap, the depth of the hole trap, and where the recombination will take place. This has all been tested and verified for the lanthanides in GdAlO3 (Luo et al., J. Phys. Chem. C., 2016, 120, 5916). In this work, Cr3+ is combined with various trivalent lanthanides in GdAlO3. By combining thermoluminescence with optical spectroscopy data, a consistent interpretation of all the data is obtained. Cr3+ can act both as a deep electron trap and a deep hole trap, which is different to all of the lanthanides. From the results we can deduce the location of the Cr2+ and Cr3+ levels within the band gap and with respect to the vacuum level. Besides thermoluminescence recombination via the conduction band, evidence is found for athermal (tunneling) recombination. The results for GdAlO3 are compared with the results for LaAlO3. It was found that they are related systems but LaAlO3 has a lower lying conduction band and a higher lying valence band, which reduces the trap depths of the lanthanides and Cr in a predictive fashion.","","en","journal article","","","","","","","","2019-04-17","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:0a1acd06-9e1c-4106-8cb1-5202cf2f8aa5","http://resolver.tudelft.nl/uuid:0a1acd06-9e1c-4106-8cb1-5202cf2f8aa5","Insight into Eu redox and Pr3+ 5d emission in KSrPO4 by VRBE scheme construction","Zhou, Rongfu (Sun Yat-sen University); Lin, Litian (Sun Yat-sen University); Liu, Chunmeng (Sun Yat-sen University); Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy); Tao, Ye (Institute of High Energy Physics Chinese Academy of Science); Huang, Yan (Institute of High Energy Physics Chinese Academy of Science); Liang, Hongbin (Sun Yat-sen University)","","2018","A series of Ln-doped KSrPO4 (Ln = Ce3+, Eu3+, Eu2+, Pr3+) phosphors are prepared through a high-temperature solid-state method. The KSrPO4 compound is confirmed to possess a β-K2SO4 structure with the Pnma group by Rietveld refinement, and the temperature-dependent lattice parameters are investigated with the powder X-ray diffraction results at different temperatures. Ce3+ and Eu3+ ions are introduced to probe the crystal field strength (CFS) and the lanthanide site symmetry by using VUV-UV-vis spectroscopy. The temperature-dependent luminescence properties of KSrPO4: Ce3+/Eu2+ exhibit an excellent thermal stability of Ce3+/Eu2+ luminescence. Based on the VUV-UV-vis spectra of Ce3+ and Eu3+ doped KSrPO4, the vacuum referred binding energy (VRBE) scheme is constructed to understand the redox properties of Eu, the 5d energy levels of Pr3+ and the thermal quenching characteristics of Ce3+ and Eu2+ luminescence.","","en","journal article","","","","","","Accepted Author Manuscript","","2019-01-02","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:02665227-b851-46f6-a125-cd952472aa22","http://resolver.tudelft.nl/uuid:02665227-b851-46f6-a125-cd952472aa22","Bi3+ acting both as an electron and as a hole trap in La-, Y-, and LuPO4","Lyu, T. (TU Delft RST/Fundamental Aspects of Materials and Energy); Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy)","","2018","The vacuum referred binding energy (VRBE)-guided design of Bi3+-based storage and afterglow materials together with charge carrier trapping processes is explored with a study on bismuth- and lanthanide-doped rare earth ortho-phosphates. By combining Bi3+ with the shallow hole trap of Tb3+ or Pr3+, Bi3+ appears to act as a deep electron trap and as a hole recombination center in YPO4. Combining Bi3+ with the deep electron trap of Tm3+, Sm3+, Yb3+, or Eu3+, Bi3+ appears to act as a shallow hole trap in YPO4. Here recombination is also realized by means of hole release instead of more commonly reported electron release. Holes are released from Bi4+ and then recombine through the valence band with the electrons trapped at Ln2+ to produce Ln3+ 4f-4f emission. Lu3+ was introduced into YPO4 to engineer the valence band (VB) energy and to tailor the hole trap depth of Bi3+ in Y1-xLuxPO4 solid solutions. The results show that with increasing x the VRBE at the valence band top moves downward and the hole trap depth of Bi3+ increases. With a deep understanding of the Bi2+ and Bi3+ trap level locations and on the charge carrier trapping process, this work broadens the avenue to explore new persistent luminescence and storage materials using Bi3+ both as electron and hole traps.","","en","journal article","","","","","","Accepted Author Manuscript","","2019-05-14","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:588a54ef-2595-4f95-96d9-e4b40599f012","http://resolver.tudelft.nl/uuid:588a54ef-2595-4f95-96d9-e4b40599f012","Time-resolved gamma spectroscopy of single events","Wolszczak, W.W. (TU Delft RST/Luminescence Materials); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2018","In this article we present a method of characterizing scintillating materials by digitization of each individual scintillation pulse followed by digital signal processing. With this technique it is possible to measure the pulse shape and the energy of an absorbed gamma photon on an event-by-event basis. In contrast to time-correlated single photon counting technique, the digital approach provides a faster measurement, an active noise suppression, and enables characterization of scintillation pulses simultaneously in two domains: time and energy. We applied this method to study the pulse shape change of a CsI(Tl) scintillator with energy of gamma excitation. We confirmed previously published results and revealed new details of the phenomenon.","CsI(Tl); Data acquisition; Digital signal processing; Gamma spectroscopy; Pulse shape analysis; Time-resolved gamma spectroscopy","en","journal article","","","","","","Accepted Author Manuscript","","2020-01-06","","","RST/Luminescence Materials","","",""
"uuid:afce490f-a4f7-449c-9b4a-7154dce2c994","http://resolver.tudelft.nl/uuid:afce490f-a4f7-449c-9b4a-7154dce2c994","Charge carrier trapping processes in lanthanide doped La-, Gd-, Y-, and LuPO4","Lyu, T. (TU Delft RST/Fundamental Aspects of Materials and Energy); Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy)","","2017","Various methods for deliberate design electron and hole trapping materials are explored with a study on double lanthanide doped rare earth ortho phosphates. Cerium acts as recombination center while lanthanide codopants as electron trapping centers in LaPO4:0.005Ce3+,0.005Ln3+. The electron trap depth generated by lanthanide codopants can be tailored by the choice of lanthanide, and for fixed set of lanthanide dopants like in Gd1-xLaxPO4:0.005Ce3+,0.005Ho3+ solid solutions by changing x leading to conduction band (CB) engineering. Here, the electrons liberated from Ho2+ recombine through the conduction band at Ce4+ to yield Ce3+ 5d-4f emission. In contrast, samarium, europium and ytterbium are recombination centers, while Tb3+ and Pr3+ act as hole trapping centers in double lanthanide doped YPO4. For Tb3+ and Pr3+ codopants recombination is realized via hole release rather than the more common reported electron release. The holes recombine via the valence band with the electrons trapped at Yb2+, Sm2+, or Eu2+ to generate 4f-4f luminescence from Yb3+, Sm3+, or Eu3+. Lu3+ was introduced in YPO4 to tailor the valence band (VB) energy and to tune the hole trap depths of Tb3+ and Pr3+ in Y1-xLuxPO4:0.005Ln3+ solid solutions. Our results promote the deliberate design electron and hole trapping materials from deep understanding of trap level locations and on the transport and trapping processes of charge carriers.","","en","journal article","","","","","","","","2018-12-08","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:9025d3b4-8841-4692-85a1-f2ef5ed9ebce","http://resolver.tudelft.nl/uuid:9025d3b4-8841-4692-85a1-f2ef5ed9ebce","The role of Ln3+ (Ln = Eu, Yb) in persistent red luminescence in MgGeO3:Mn2+","Katayama, Y. (University of Tokyo; Kyoto University); Kayumi, T. (Kyoto University); Ueda, J. (Kyoto University); Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy); Viana, B (CNRS); Tanabe, S (Kyoto University)","","2017","In this paper, Mn2+ and Ln3+ (Ln = Eu, Yb) co-doped MgGeO3 phosphors were prepared using a solid state reaction technique, and their optical properties were investigated. Mn2+-doped samples exhibit persistent luminescence in the red region, peaking at 677 nm, because of the 4T1 → 6A1 transition of the Mn2+ ions under ultraviolet (UV) excitation. Based on the charge transfer (CT) transition of Eu3+ and the band-gap energy, energy level diagrams with divalent lanthanide ground states relative to the conduction and valence band edges were constructed. ΔE(Ln), (Ln = Eu, Yb), which represents the energy gaps between the divalent lanthanide ground states and the bottom of the conduction band, were found to be 0.95 and 0.52 eV, respectively. Compared to a Mn2+ singly-doped sample, the thermoluminescence (TL) glow curves of the Mn2+–Eu3+ co-doped sample and the Mn2+–Yb3+ co-doped sample showed an additional TL glow peak at approximately 502 and 332 K with trap depths (Etrap) of 1.49 and 0.99 eV, respectively. The correspondence of Etrap with ΔE(Ln) suggests that Eu3+ and Yb3+ themselves work as electron traps in the MgGeO3:Mn2+ phosphors. We have also demonstrated that the Mn2+–Eu3+ co-doped material could be a good probe with photo-stimulated functions for long-term in vivo imaging owing to its deeper trap depth.","","en","journal article","","","","","","","","2018-08-04","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:2a3cbde1-c034-45b5-b573-afb15938c1c5","http://resolver.tudelft.nl/uuid:2a3cbde1-c034-45b5-b573-afb15938c1c5","The Bi3+ 6s and 6p electron binding energies in relation to the chemical environment of inorganic compounds","Awater, R.H.P. (TU Delft RST/Fundamental Aspects of Materials and Energy); Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy)","","2017","This paper provides an overview and interpretation of the spectroscopic data of the Bi3+ activator ion in 117 different inorganic compounds. The energies of the metal-to-metal charge transfer and the interconfigurational transitions of Bi3+ were collected from the archival literature. Using these energies, in combination with the electron binding energies in the host conduction and valence band, the binding energies in the 6s ground state and 6p excited state were determined relative to the vacuum level. The locations of the Bi3+ energy levels within the forbidden gap of the host compound provides valuable insight in the physical properties of the Bi3+ activator ion in different compounds.","Bi; Chemical shift; Electron binding energies; Electronic structure; Metal-to-metal charge transfer","en","review","","","","","","Accepted Author Manuscript","","2019-01-03","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:0b6a41ca-1695-466f-a79c-a71a4c6831c0","http://resolver.tudelft.nl/uuid:0b6a41ca-1695-466f-a79c-a71a4c6831c0","Thermal ionization and thermally activated crossover quenching processes for 5d-4f luminescence in Y3 A l5-x G ax O12: P r3+","Ueda, J. (TU Delft RST/Fundamental Aspects of Materials and Energy; Kyoto University; Universiteit Utrecht); Meijerink, Andries (Universiteit Utrecht); Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy); bos, A.J.J. (TU Delft RST/Fundamental Aspects of Materials and Energy); Tanabe, Setsuhisa (Kyoto University)","","2017","We investigated thermally activated ionization and thermally activated crossover as the two possibilities of quenching of 5d luminescence in Pr3+-doped Y3Al5-xGaxO12. Varying the Ga content x gives the control over the relative energy level location of the 5d and 4f2:PJ3 states of Pr3+ and the host conduction band (CB). Temperature-dependent luminescence lifetime measurements show that the 5d luminescence quenching temperature T50% increases up to x=2 and decreases with further increasing Ga content. This peculiar behavior is explained by a unique transition between the two quenching mechanisms which have an opposite dependence of thermal quenching on Ga content. For low Ga content, thermally activated crossover from the 4f5d state to the 4f2(PJ3) states is the operative quenching mechanism. With increasing Ga content, the activation energy for thermally activated crossover becomes larger, as derived from the configuration coordinate diagram, while from the vacuum referred binding energy diagram the activation energy of thermal ionization becomes smaller. Based on these results, we demonstrated that the thermal quenching of Pr3+:5d1-4f luminescence in Y3Al5-xGaxO12 with x=0,1,2 is a thermally activated crossover while for x=3,4,5 it results from the thermal ionization.","","en","journal article","","","","","","","","","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:dfc0480b-8910-4a95-b861-d0d6941e82a5","http://resolver.tudelft.nl/uuid:dfc0480b-8910-4a95-b861-d0d6941e82a5","Charge Carrier Trapping Processes in RE2O2S (RE = La, Gd, Y, and Lu)","Luo, H. (TU Delft RST/Fundamental Aspects of Materials and Energy); bos, A.J.J. (TU Delft RST/Fundamental Aspects of Materials and Energy); Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy)","","2017","Two different charge carrier trapping processes have been investigated in RE2O2S:Ln3+ (RE = La, Gd, Y, and Lu; Ln = Ce, Pr, and Tb) and RE2O2S:M (M = Ti4+ and Eu3+). Cerium, praseodymium and terbium act as recombination centers and hole trapping centers while host intrinsic defects provide the electron trap. The captured electrons released from the intrinsic defects recombine at Ce4+, Pr4+, or Tb4+ via the conduction band. On the other hand, Ti4+ and Eu3+ act as recombination centers and electron trapping centers while host intrinsic defects act as hole trapping centers. For these codopants we find evidence that recombination is by means of hole release instead of electron release. The released holes recombine with the trapped electrons on Ti3+ or Eu2+ and yield broad Ti4+ yellow-red charge transfer (CT) emission or characteristic Eu3+ 4f–4f emission. We will conclude that the afterglow in Y2O2S:Ti4+, Eu3+ is due to hole release instead of more common electron release.","","en","journal article","","","","","","","","","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:cde5be5d-9bdd-476d-8cc8-8c8d4ffe8429","http://resolver.tudelft.nl/uuid:cde5be5d-9bdd-476d-8cc8-8c8d4ffe8429","Luminescent properties and energy level structure of CaZnOS:Eu2+","Budde, B (Student TU Delft); Luo, H. (TU Delft RST/Fundamental Aspects of Materials and Energy); Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy); van der Kolk, E. (TU Delft RST/Fundamental Aspects of Materials and Energy)","","2017","In this work it is shown that CaZnOS:Eu2+ has no Eu2+ emission even at low temperature. The observed and earlier reported red emission originates from a CaS:Eu2+ impurity phase. By means of washing the as-prepared samples with diluted nitride acid, we were able to remove the CaS impurity phase and study the Eu2+ emission in the pure CaZnOS phase. A clear relation was found between the red emission intensity, the CaS XRD line intensities and the nitric acid solution washing time, with zero intensity after prolonged washing. A so-called VRBE (vacuum referred binding energy)-diagram was constructed showing the energy of the 4fn and 4fn-15d1 states of the divalent and trivalent rare earth ions as dopants in CaZnOS with respect to the vacuum energy. This diagram shows that the 5d-levels of Eu2+ are located in the conduction band, which explains the absence of 5d→4f emission. By comparing the VRBE diagram with diagrams of other related compounds like CaO, CaS, ZnO and ZnS it becomes clear that the Eu2+ luminescence quenching is caused by a low lying conduction band, typical for Zn-based compounds.","CaZnOS; Energy level; Eu","en","journal article","","","","","","Accepted Author Manuscript","","2019-05-08","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:90940924-00ae-4229-9047-b46fe12bda3c","http://resolver.tudelft.nl/uuid:90940924-00ae-4229-9047-b46fe12bda3c","Vacuum referred binding energy of 3d transition metal ions for persistent and photostimulated luminescence phosphors of cerium-doped garnets","Ueda, J. (Kyoto University); Hashimoto, Atsunori (Kyoto University); Takemura, Shota (Kwansei Gakuin University); Ogasawara, Kazuyoshi (Kwansei Gakuin University); Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy); Tanabe, Setsuhisa (Kyoto University)","","2017","The Y3Al5−xGaxO12(YAGG):Ce3+-Cr3+ persistent phosphor is one of the materials in which Cr3+ ions act as electron traps. The possibility of electron traps by other transition metal ions (TM3+, TM = Sc, Ti, V, Cr, Fe) was investigated and those electron trap depth was compared with each other. In the thermoluminescence (TL) glow curves, the YAGG:Ce3+ samples co-doped with different TM3+ ions show different TL glow peak temperatures (i.e. different electron trap depth). The estimated vacuum referred binding energy of TM2+ from the trap depth shows a zig-zag curve, which is found to be originated from the different 3d electron energies affected by a number of d electron, nuclear charge and crystal field splitting. Utilizing the obtained TM2+ zig-zag curve, a new persistent phosphor of Y3Al2Ga3O12:Ce3+-Sc3+ and a photostimulated phosphor of Y3Al2Ga3O12:Ce3+-V3+ were successfully developed.","","en","journal article","","","","","","Accepted Author Manuscript","","2019-07-12","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:db8b1a35-0160-4ce0-bcef-48cec1201465","http://resolver.tudelft.nl/uuid:db8b1a35-0160-4ce0-bcef-48cec1201465","Thermal quenching of Eu2+ emission in Ca- and Sr-Ga2S4 in relation with VRBE schemes","Dobrowolska, A.P. (TU Delft RST/Fundamental Aspects of Materials and Energy; Wroclaw University of Economics and Business); Dierre, B.F.P.R. (TU Delft RST/Fundamental Aspects of Materials and Energy); Fang, C.M. (Brunel University); Hintzen, H.T.J.M. (TU Delft RST/Fundamental Aspects of Materials and Energy); Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy)","","2016","Structural and optical properties of MGa2S4 (M = Mg, Zn, Ca, Sr, Ba) compounds have been compared, and the vacuum referred binding energy (VRBE) schemes were constructed for the lanthanide ions in the iso-structural compounds CaGa2S4 and SrGa2S4 employing literature data. The VRBE of an electron in the 5d excited state of Eu2+ was found at 0.75 and 0.97 eV below the bottom of the conduction band (CB) in CaGa2S4:Eu and SrGa2S4:Eu, respectively. Such differences explains the unexpected higher thermal quenching temperature reported for Eu2+-doped SrGa2S4 (T50% = ∼475 K) compared to Eu2+-doped CaGa2S4 (T50% = 400 K) The significantly lower VRBE at the CB-bottom in CaGa2S4 versus SrGa2S4 may be explained by the shorter Ga-S bond lengths in SrGa2S4.","SrGa2S4; CaGa2S4; Thiogallate; VRBE; Thermal quenching","en","journal article","","","","","","Accepted Author Manuscript","","2019-01-04","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:f897c5c1-9a63-4053-ad8b-a6caa9b14cfe","http://resolver.tudelft.nl/uuid:f897c5c1-9a63-4053-ad8b-a6caa9b14cfe","Experiments and theory of 138 La radioactive decay","Quarati, F.G.A. (TU Delft RST/Luminescence Materials; Gonitec B.V.); Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy); Mougeot, X. (CEA-Saclay)","","2016","","","en","journal article","","","","","","","","2018-02-01","","","RST/Luminescence Materials","","",""
"uuid:9dc6cf03-02a0-49f6-ade5-17af716d561b","http://resolver.tudelft.nl/uuid:9dc6cf03-02a0-49f6-ade5-17af716d561b","Gebiedskenmerken als basis voor herontwerp OV-netwerk Den Haag","Dorenbos, G.; Nijënstein, S. (HTM Personenvervoer N.V.); van Oort, N. (TU Delft Transport and Planning)","","2016","Hoe zou het OV van Den Haag eruit zien als we het opnieuw zouden ontwerpen? Om verbetermogelijkheden in het huidige netwerk op te sporen hebben we een ontwerpmethodiek toegepast met als uitgangspunt een uitgebreide demografische analyse. De methodiek bestond uit vier stappen: In stap 1 zijn demografische gegevens gebruikt voor het genereren van gegevens over potentieel reizigersgedrag. Hieruit zijn in de volgende stap HerkomstBestemmings-matrices gegenereerd door middel van een zwaartekrachtsmodel. Het ontwerpen van het netwerk vond plaats in stap drie door een minimaal aantal kortste schakels aan te brengen tussen wijken totdat alle wijken ontsloten zijn door middel van een “kortste schakel netwerk”. Hier worden ‘shortcuts’ aan toegevoegd om tegemoet te komen aan drukke relaties volgens de HB-matrix. Op deze manier ontstaat er een ‘ideaal’ netwerk van wijk-wijk relaties. Om in de laatste stap de frequenties van de links te bepalen, zijn de reizigers uit de HB-matrix toegedeeld volgens een ‘all-or-nothing assignment’. Het resultaat is een netwerk van links en nodes die de zwaartepunten van de wijken in Den Haag met elkaar en met de stations verbinden. Uit de vergelijking tussen het nieuwe en bestaande netwerk blijkt dat het huidige tramnetwerk van Den Haag goed voldoet aan de vraag. Er zijn wijken die nog beter ontsloten zouden kunnen worden (zoals Benoordenhout en Binckhorst) en wijken waar directere verbindingen naar het centrum zouden kunnen worden gecreëerd (zoals voor de wijken in het zuiden van Den Haag en Wateringen). In dit paper wordt een aantal concrete voorstellen gedaan voor deze verbeteringen. Deze ontwerpmethodiek blijkt goed toepasbaar en waardevol voor het vinden van netwerkverbeteringen en is ook interessant voor andere steden en gebieden om de potentiele reizigersvraag beter te kunnen koppelen aan het OV-netwerk. De methodiek kan daarbij gebruikt worden als een toetsing van het bestaande netwerk of voor het ontwerpen van een nieuw netwerk.","","en","conference paper","","","","","","","","","","","Transport and Planning","","",""
"uuid:1924e45a-e2dd-4d03-9d48-166ca20fe520","http://resolver.tudelft.nl/uuid:1924e45a-e2dd-4d03-9d48-166ca20fe520","Design of broadband high-efficiency superconducting-nanowire single photon detectors","Redaelli, L. (Université Grenoble Alpes; CEA Grenoble); Bulgarini, G. (Single Quantum); Dobrovolskiy, S. (Single Quantum); Dorenbos, S. N. (Single Quantum); Zwiller, V.G. (TU Delft QN/Zwiller Lab; Université Grenoble Alpes; KTH Royal Institute of Technology; Kavli institute of nanoscience Delft); Monroy, E (Université Grenoble Alpes; CEA Grenoble); Gerard, J.A. (Université Grenoble Alpes; CEA Grenoble)","","2016","In this paper several designs to maximize the absorption efficiency of superconducting-nanowire single-photon detectors are investigated. Using a simple optical cavity consisting of a gold mirror and a SiO2 layer, the absorption efficiency can be boosted to over 97%: this result is confirmed experimentally by the realization of an NbTiN-based detector having an overall system detection efficiency of 85% at 1.31 μm. Calculations show that by sandwiching the nanowire between two dielectric Bragg reflectors, unity absorption (>99.9%) could be reached at the peak wavelength for optimized structures. To achieve broadband high efficiency, a different approach is considered: a waveguide-coupled detector. The calculations performed in this work show that, by correctly dimensioning the waveguide and the nanowire, polarization-insensitive detectors absorbing more than 95% of the injected photons over a wavelength range of several hundred nm can be designed. We propose a detector design making use of GaN/AlN waveguides, since these materials allow lattice-matched epitaxial deposition of Nb(Ti)N films and are transparent on a very wide wavelength range.","microcavity; nitride; photodetectors; single-photon detectors; SNSPD; superconducting-nanowire detectors; waveguide","en","journal article","","","","","","Accepted Author Manuscript","","2017-05-06","","","QN/Zwiller Lab","","",""
"uuid:f28605e8-78df-4443-89f5-2102fc42f510","http://resolver.tudelft.nl/uuid:f28605e8-78df-4443-89f5-2102fc42f510","Electronic structure and site occupancy of lanthanide-doped (Sr, ca)3(Y, lu)2Ge3O12 garnets: A spectroscopic and first-principles study","Luo, H. (TU Delft RST/Fundamental Aspects of Materials and Energy); Ning, Lixin (Anhui Normal University); Dong, Yuanyuan (Anhui Normal University); bos, A.J.J. (TU Delft RST/Luminescence Materials); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2016","Photoluminescence excitation (PLE) and emission spectra (PL) of undoped (Sr, Ca)3(Y, Lu)2Ge3O12 as well as Eu3+- and Ce3+-doped samples have been investigated. The PL spectra show that Eu3+ enters into both dodecahedral (Ca, Sr) and octahedral (Y, Lu) sites. Ce3+ gives two broad excitation bands in the range of 200−450 nm. First-principle calculations for Ce3+ on both dodecahedral and octahedral sites provide sets of 5d excited level energies that are consistent with the experimental results. Then the vacuum referred binding energy diagrams for (Sr, Ca)3(Y, Lu)2Ge3O12 have been constructed with the lanthanide dopant energy levels by utilizing spectroscopic data. The Ce3+ 5d excited states are calculated by first-principles calculations. Thermoluminescence (TL) glow curves of (Ce3+, Sm3+)-codoped (Sr, Ca)3(Y, Lu)2Ge3O12 samples show a good agreement with the prediction of lanthanide trapping depths derived from the energy level diagram. Finally, the energy level diagram is used to explain the low thermal quenching temperature of Ce3+ and the absence of afterglow in (Sr, Ca)3(Y, Lu)2Ge3O12.","","en","journal article","","","","","","","","2017-11-25","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:4ab682b6-44e6-45f7-b86a-ac12a7d2cab7","http://resolver.tudelft.nl/uuid:4ab682b6-44e6-45f7-b86a-ac12a7d2cab7","Vacuum Referred Binding Energy of the Single 3d, 4d, or 5d Electron in Transition Metal and Lanthanide Impurities in Compounds","Rogers, E.G.; Dorenbos, P.","","2014","The vacuum referred binding energy (VRBE) of the single electron in the lowest energy 3d level of Sc2 +, V4 +, Cr5 +, the lowest 4d level of Y2 +, Zr3 +, Nb4 +, Mo5 + and the lowest 5d level of Ta4 +, and W5 + in various compounds are determined by means of the chemical shift model. They will be compared with the VRBE in the already established lowest 3d level of Ti3 + and the lowest 5d level of Eu2 + and Ce3 +. Clear trends with changing charge of the transition metal (TM) cation and with changing principle quantum number n = 3, 4, or 5 of the nd level will be identified. This work will demonstrate that the trends correlate with the VRBE in the free ion nd TM cation level. The acquired knowledge on the VRBE of the electron in the nd TM impurity levels but also on TM based compounds with nd type of conduction band bottom provides new insight in the luminescence properties of TM activated compounds.","","en","journal article","Electrochemical Society","","","","","","","","Applied Sciences","RST/Radiation, Science and Technology","","","",""
"uuid:c2564d3c-4cd7-4c5c-98aa-a88e0b7066ee","http://resolver.tudelft.nl/uuid:c2564d3c-4cd7-4c5c-98aa-a88e0b7066ee","Scintillation properties of Ca co-doped L(Y)SO:Ce between 193 K and 373 K for TOF-PET/MRI","Ter Weele, D.N.; Schaart, D.R.; Dorenbos, P.","","2014","","","en","journal article","SpringerOpen","","","","","","","","Applied Sciences","RST/Radiation, Science and Technology","","","",""
"uuid:c287c522-ca1d-4b86-a844-3aec4a890d9e","http://resolver.tudelft.nl/uuid:c287c522-ca1d-4b86-a844-3aec4a890d9e","Vacuum Referred Binding Energies of the Lanthanides in Transition Metal Oxide Compounds","Dorenbos, P.; Rogers, E.G.","","2014","The electronic level schemes for divalent and trivalent lanthanide ions in rare earth (La, Gd, Y, Lu, Sc) vanadate, niobate, tantalate, and in alkaline earth (Ba, Sr, Ca, Mg) titanate, molybdate, and tungstate compounds are presented. Use is made of data from luminescence excitation and absorption spectra of lanthanide (mostly Eu3 +, Pr3 +, and Tb3 +) impurities in those compounds. By means of the chemical shift model, binding energies, relative to the vacuum energy, of electrons in the impurity levels and the host bands are obtained. It reveals clear trends in conduction band and valence band energy with changing size of the rare earth or the alkaline earth ion. The bottom of the conduction band is dominated by 3d, 4d, or 5d orbitals, and it is found that the binding energy at the conduction band bottom tends to decrease with higher orbital number.","","en","journal article","The Electrochemical Society","","","","","","","","Applied Sciences","RST/Radiation, Science and Technology","","","",""
"uuid:3615aa86-e542-4e5c-ba48-c3cb3a202b1b","http://resolver.tudelft.nl/uuid:3615aa86-e542-4e5c-ba48-c3cb3a202b1b","33000 photons per MeV from mixed (Lu0.75Y0.25)3Al5O12:Pr scintillator crystals","Drozdowski, W.; Brylew, K.; Wojtowicz, A.J.; Kisielewski, J.; Swirkowicz, M.; Lukasiewicz, T.; De Haas, J.T.M.; Dorenbos, P.","","2014","(LuxY1-x)3Al5O12:Pr (x = 0.25, 0.50, 0.75) crystals have been grown by the Czochralski method and their scintillation properties have been examined. Compared to the well-respected LuAG:Pr scintillator, which has so extensively been studied in the recent years, the new mixed LuYAG:Pr crystals display markedly higher light yields, regardless of the value of x. In particular, (Lu0.75Y0.25)3Al5O12:0.2%Pr characterized by a yield of 33000 ph/MeV, an energy resolution of 4.4% (at 662 keV), and a density of 6.2 g/cm3, seems to be an ideal candidate to supercede Lu3Al5O12:0.2%Pr (19000 ph/MeV, 4.6%, 6.7 g/cm3) in various applications. The observed enhancement of light output following the partial substitution of lutetium by yttrium is most probably related to some specific differences in distributions of shallow traps in particular materials.","rare-earth-doped materials; detectors; energy transfer; scintillation","en","journal article","Optical Society of America","","","","","","","","Applied Sciences","RST/Radiation, Science and Technology","","","",""
"uuid:bceb93eb-8bde-4916-92e1-237513c6a2eb","http://resolver.tudelft.nl/uuid:bceb93eb-8bde-4916-92e1-237513c6a2eb","The Electronic Structure of Lanthanide Impurities in TiO2, ZnO, SnO2, and Related Compounds","Dorenbos, P.","","2013","The vacuum referred binding energy of electrons in the 4fn levels for all divalent and trivalent lanthanide impurity states in TiO2, ZnO, SnO2, and related compounds MTiO3 and MSnO3 (M = Ca2 +, Sr2 +, Ba2 +) and Ca2SnO4 are presented. They are obtained by collecting data from the literature on the spectroscopy of lanthanide ions, and by combining that data with the chemical shift model. The model provides the energy at the top of the valence band and at the bottom of the conduction band, and it will be shown that those energies are in excellent agreement with what is known from techniques like photo-electron spectroscopy and electrochemical studies. Electronic level diagrams are presented that explain and predict aspects like absence or presence of lanthanide 4f-4f or 5d-4f emissions and the preferred lanthanide valence.","","en","journal article","The Electrochemical Society","","","","","","","","Applied Sciences","RST/Radiation, Science and Technology","","","",""
"uuid:a263a6a4-dab4-4b89-8c4d-557ed7ee5388","http://resolver.tudelft.nl/uuid:a263a6a4-dab4-4b89-8c4d-557ed7ee5388","Photon pair generation in a silicon micro-ring resonator with reverse bias enhancement","Engin, E.; Bonneau, D.; Natarajan, C.M.; Clark, A.S.; Tanner, M.G.; Hadfield, R.H.; Dorenbos, S.N.; Zwiller, V.G.; Ohira, K.; Suzuki, N.; Yoshida, H.; Iizuka, N.; Ezaki, M.; OBrien, J.L.; Thompson, M.G.","","2013","Photon sources are fundamental components for any quantum photonic technology. The ability to generate high count-rate and low-noise correlated photon pairs via spontaneous parametric down-conversion using bulk crystals has been the cornerstone of modern quantum optics. However, future practical quantum technologies will require a scalable integration approach, and waveguide-based photon sources with high-count rate and low-noise characteristics will be an essential part of chip-based quantum technologies. Here, we demonstrate photon pair generation through spontaneous four-wave mixing in a silicon micro-ring resonator, reporting separately a maximum coincidence-to-accidental (CAR) ratio of 602 ± 37 (for a generation rate of 827kHz), and a maximum photon pair generation rate of 123 MHz ± 11 kHz (with a CAR value of 37). To overcome free-carrier related performance degradations we have investigated reverse biased p-i-n structures, demonstrating an improvement in the pair generation rate by a factor of up to 2 with negligible impact on CAR.","","en","journal article","Optical Society of America","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:04aaac8d-1f90-461a-add9-acb2f415c75b","http://resolver.tudelft.nl/uuid:04aaac8d-1f90-461a-add9-acb2f415c75b","Energy resolution and related charge carrier mobility in LaBr3:Ce scintillators","Khodyuk, I.V.; Quarati, F.G.A.; Alekhin, M.S.; Dorenbos, P.","","2013","The scintillation response of LaBr3:Ce scintillation crystals was studied as function of temperature and Ce concentration with synchrotron X-rays between 9?keV and 100?keV. The results were analyzed using the theory of carrier transport in wide band gap semiconductors to gain new insights into charge carrier generation, diffusion, and capture mechanisms. Their influence on the efficiency of energy transfer and conversion from X-ray or ?-ray photon to optical photons and therefore on the energy resolution of lanthanum halide scintillators was studied. From this, we will propose that scattering of carriers by both the lattice phonons and by ionized impurities are key processes determining the temperature dependence of carrier mobility and ultimately the scintillation efficiency and energy resolution. When assuming about 100?ppm ionized impurity concentration in 0.2% Ce3+ doped LaBr3, mobilities are such that we can reproduce the observed temperature dependence of the energy resolution, and in particular, the minimum in resolution near room temperature is reproduced.","charge carriers; ionization; carrier mobility; photons; ionizing radiation; phonons; diffusion; doping; carrier scattering; electron hole","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","RST/Radiation, Science and Technology","","","",""
"uuid:f0981365-0df0-419e-a54c-78b48e1c344a","http://resolver.tudelft.nl/uuid:f0981365-0df0-419e-a54c-78b48e1c344a","Improvement of LaBr3:5%Ce scintillation properties by Li1, Na1, Mg21, Ca21, Sr21, and Ba21 co-doping","Alekhin, M.S.; Biner, D.A.; Krämer, K.W.; Dorenbos, P.","","2013","This paper reports on the effects of Liþ, Naþ, Mg2þ, Ca2þ, Sr2þ, and Ba2þ co-doping on the scintillation properties of LaBr3:5%Ce3þ. Pulse-height spectra of various gamma and X-ray sources with energies from 8 keV to 1.33 MeV were measured from which the values of light yield and energy resolution were derived. Sr2þ and Ca2þ co-doped crystals showed excellent energy resolution as compared to standard LaBr3:Ce. The proportionality of the scintillation response to gamma and X-rays of Ca2þ, Sr2þ, and Ba2þ co-doped samples also considerably improves. The effects of the co-dopants on emission spectra, decay time, and temperature stability of the light yield were studied. Multiple thermoluminescence glow peaks, decrease of the light yield at temperatures below 295 K, and additional long scintillation decay components were observed and related to charge carrier traps appearing in LaBr3:Ce3þ with Ca2þ, Sr2þ, and Ba2þ co-doping.","","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","RST/Radiation, Science and Technology","","","",""
"uuid:48f08a52-1066-47e7-9531-6c5870526e23","http://resolver.tudelft.nl/uuid:48f08a52-1066-47e7-9531-6c5870526e23","Capacitive readout and gating of superconducting single photon detectors","Azzouz, H.; Heeres, R.W.; Dorenbos, S.N.; Schouten, R.N.; Zwiller, V.","","2013","We propose and develop a readout scheme for superconducting single-photon detectors based on an integrated circuit, relaxing the need for large bandwidth amplification and resulting in voltage steps proportional to the number of detected photons. We also demonstrate time gating, to filter scattered light in time and reduce dark counts. This could lead to a higher signal-to-noise ratio. The gate pulse is generated on the detection of a photon created by a spontaneous parametric down-conversion source, heralding the presence of a second photon. These two schemes could find applications within advanced multi-array imaging detection systems.","integrated optoelectronics; light scattering; optical pulse generation; readout electronics; superconducting photodetectors","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:05d6d170-cdac-4a31-97c1-8ce3c7107b85","http://resolver.tudelft.nl/uuid:05d6d170-cdac-4a31-97c1-8ce3c7107b85","Improvement of ?-ray energy resolution of LaBr3:Ce3+ scintillation detectors by Sr2+ and Ca2+ co-doping","Alekhin, M.S.; De Haas, J.T.M.; Khodyuk, I.V.; Krämer, K.W.; Menge, P.R.; Ouspenski, V.; Dorenbos, P.","","2013","Commercially available LaBr3:5% Ce3+ scintillators show with photomultiplier tube readout about 2.7% energy resolution for the detection of 662?keV ?-rays. Here we will show that by co-doping LaBr3:Ce3+ with Sr2+ or Ca2+ the resolution is improved to 2.0%. Such an improvement is attributed to a strong reduction of the scintillation light losses that are due to radiationless recombination of free electrons and holes during the earliest stages (1–10?ps) inside the high free charge carrier density parts of the ionization track.","gamma-ray detection; nuclear electronics; particle tracks; photomultipliers; readout electronics; solid scintillation detectors","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","RST/Radiation, Science and Technology","","","",""
"uuid:e7cbe9f1-12bb-4f49-920e-7c6b17eb0471","http://resolver.tudelft.nl/uuid:e7cbe9f1-12bb-4f49-920e-7c6b17eb0471","Kilometer-range, high resolution depth imaging via 1560 nm wavelength single-photon detection","McCarthy, A.; Krichel, N.J.; Gemmell, N.R.; Ren, X.; Tanner, M.G.; Dorenbos, S.N.; Zwiller, V.; Hadfield, R.H.; Buller, G.S.","","2013","This paper highlights a significant advance in time-of-flight depth imaging: by using a scanning transceiver which incorporated a free-running, low noise superconducting nanowire single-photon detector, we were able to obtain centimeter resolution depth images of low-signature objects in daylight at stand-off distances of the order of one kilometer at the relatively eye-safe wavelength of 1560 nm. The detector used had an efficiency of 18% at 1 kHz dark count rate, and the overall system jitter was ~100 ps. The depth images were acquired by illuminating the scene with an optical output power level of less than 250 µW average, and using per-pixel dwell times in the millisecond regime.","","en","journal article","Optical Society of America","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:c3a89777-0d06-4e65-a7c3-5af5b1bb5da3","http://resolver.tudelft.nl/uuid:c3a89777-0d06-4e65-a7c3-5af5b1bb5da3","Singlet oxygen luminescence detection with a fiber-coupled superconducting nanowire single-photon detector","Gemmell, N.R.; McCarthy, A.; Liu, B.; Tanner, M.G.; Dorenbos, S.N.; Zwiller, V.; Patterson, M.S.; Buller, G.S.; Wilson, B.C.; Hadfield, R.H.","","2013","Direct monitoring of singlet oxygen (1O2) luminescence is a particularly challenging infrared photodetection problem. 1O2, an excited state of the oxygen molecule, is a crucial intermediate in many biological processes. We employ a low noise superconducting nanowire single-photon detector to record 1O2 luminescence at 1270 nm wavelength from a model photosensitizer (Rose Bengal) in solution. Narrow band spectral filtering and chemical quenching is used to verify the 1O2 signal, and lifetime evolution with the addition of protein is studied. Furthermore, we demonstrate the detection of 1O2 luminescence through a single optical fiber, a marked advance for dose monitoring in clinical treatments such as photodynamic therapy.","","en","journal article","Optical Society of America","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:4daa330a-35cb-4fb4-a3ad-f6eb2f30d6c7","http://resolver.tudelft.nl/uuid:4daa330a-35cb-4fb4-a3ad-f6eb2f30d6c7","Photoluminescence Properties of Red-Emitting Mn2+-Activated CaAlSiN3 Phosphor for White-LEDs","Zhang, Z.; Delsing, A.C.A.; Notten, P.H.L.; Zhao, J.; Dorenbos, P.; Hintzen, H.T.","","2013","Mn2+-doped CaAlSiN3 phosphors have been prepared by a solid-state reaction method at high temperature and the solubility of Mn2+ in the host lattice as well as their photoluminescence properties were investigated. In CaAlSiN3, not only Ca2+ sites, but also Al3+ sites can be substituted by Mn2+ ions. CaAlSiN3 : Mn2+ absorbs blue light in the spectral range of 440–460 nm, and exhibits a broad band emission in the wavelength range of 475–750 nm, which can be ascribed to the 4T1 (4G) ? 6A1 (6S) transition of Mn2+ located at two different sites in CaAlSiN3. The emission bands at lower energy (15,950 cm?1 or 627 nm) and higher energy (18,250 cm?1 or 548 nm) are assigned to the Mn2+ locating at the Al site (MnAl) and Ca site (MnCa), respectively with energy transfer from MnCa to MnAl. In addition, the integral luminescence intensity only decreases to about 94% at 150?C of the value at 50?C, which is of great interest for the applications of white-LEDs.","","en","journal article","The Electrochemical Society","","","","","","","","Applied Sciences","RST/Radiation, Science and Technology","","","",""
"uuid:9fc859e6-20cf-4729-b2e5-f606cebaf787","http://resolver.tudelft.nl/uuid:9fc859e6-20cf-4729-b2e5-f606cebaf787","Determining binding energies of valence-band electrons in insulators and semiconductors via lanthanide spectroscopy","Dorenbos, P.","","2013","Models and methods to determine the absolute binding energy of 4f-shell electrons in lanthanide dopants will be combined with data on the energy of electron transfer from the valence band to a lanthanide dopant. This work will show that it provides a powerful tool to determine the absolute binding energy of valence band electrons throughout the entire family of insulator and semiconductor compounds. The tool will be applied to 28 fluoride, oxide, and nitride compounds providing the work function and electron affinity together with the location of the energy levels of all divalent and all trivalent lanthanide dopants with an accuracy that surpasses that of traditional methods like photoelectron spectroscopy. The 28 compounds were selected to demonstrate how work function and electron affinity change with composition and structure, and how electronic structure affects the optical properties of the lanthanide dopants. Data covering more than 1000 different halide (F, Cl, Br, I), chalcogenide (O, S, Se), and nitride compounds are available in the archival literature enabling us to routinely establish work function and electron affinity for this much wider collection of compounds.","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","RST/Radiation, Science and Technology","","","",""
"uuid:dc55dfc9-87d2-44a2-83ce-9ac2ee7c8059","http://resolver.tudelft.nl/uuid:dc55dfc9-87d2-44a2-83ce-9ac2ee7c8059","Quantum detector tomography of a time-multiplexed superconducting nanowire single-photon detector at telecom wavelengths","Natarajan, C.M.; Zhang, L.; Coldenstrodt-Ronge, H.; Donati, G.; Dorenbos, S.N.; Zwiller, V.; Walmsley, I.A.; Hadfield, R.H.","","2013","Superconducting nanowire single-photon detectors (SNSPDs) are widely used in telecom wavelength optical quantum information science applications. Quantum detector tomography allows the positive-operator-valued measure (POVM) of a single-photon detector to be determined. We use an all-fiber telecom wavelength detector tomography test bed to measure detector characteristics with respect to photon flux and polarization, and hence determine the POVM. We study the SNSPD both as a binary detector and in an 8-bin, fiber based, Time-Multiplexed (TM) configuration at repetition rates up to 4 MHz. The corresponding POVMs provide an accurate picture of the photon number resolving capability of the TM-SNSPD.","","en","journal article","Optical Society of America","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:4dc1f3f1-1fcb-4ab8-a048-c072ca4b3c4b","http://resolver.tudelft.nl/uuid:4dc1f3f1-1fcb-4ab8-a048-c072ca4b3c4b","A review on how Lanthanide impurity levels change with chemistry and structure of inorganic compounds","Dorenbos, P.","","2012","The energy of the 4f-5d transitions of divalent and trivalent lanthanide impurities in compounds depends strongly on the type of lanthanide, its valence, and the type of compound. Despite this large variability there is much systematic in 4f-5d transition energy. Once it is known for one lanthanide that for all others when in the same compound can be predicted. The same applies for the energy of electron transfer from the valence band to the 4f-shell of lanthanides which also behaves in a systematic fashion with type of lanthanide and type of compound. This work reviews my studies during the past fifteen years that are based on an analysis of data on all divalent and all trivalent lanthanides in more than 1000 different inorganic compounds collected from the archival literature. The established redshift and charge transfer models that form the basis to construct binding energy schemes showing all lanthanide levels with respect to the host bands are reviewed and the latest developments are addressed.","","en","journal article","Electrochemical Society","","","","","","","","Applied Sciences","RST/Radiation, Science and Technology","","","",""
"uuid:70092b2e-afc7-480c-85d9-b36b17420f50","http://resolver.tudelft.nl/uuid:70092b2e-afc7-480c-85d9-b36b17420f50","Measuring the quantum nature of light with a single source and a single detector","Steudle, G.A.; Schietinger, S.; Höckel, D.; Dorenbos, S.N.; Zadeh, I.E.; Zwiller, V.; Benson, O.","","2012","An elementary experiment in optics consists of a light source and a detector. Yet, if the source generates nonclassical correlations such an experiment is capable of unambiguously demonstrating the quantum nature of light. We realized such an experiment with a defect center in diamond and a superconducting detector. Previous experiments relied on more complex setups, such as the Hanbury Brown and Twiss configuration, where a beam splitter directs light to two photodetectors, creating the false impression that the beam splitter is a fundamentally required element. As an additional benefit, our results provide a simplification of the widely used photon-correlation techniques.","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:f45fe170-f5ad-4798-997f-6b26819d275f","http://resolver.tudelft.nl/uuid:f45fe170-f5ad-4798-997f-6b26819d275f","Efficient single particle detection with a superconducting nanowire","Azzouz, H.; Dorenbos, S.N.; De Vries, D.; Bermudez Urena, E.; Zwiller, V.","","2012","Detection of ?- and ?-particles is of paramount importance in a wide range of applications. Current particle detectors are all macroscopic and have limited time resolution. We demonstrate a nanoscale particle detector with a small detection volume, high detection efficiency, short dead times and low dark count levels. We measure ?- and ?-particle detection efficiencies close to unity using different sources and also demonstrate blindness towards ?-rays. Our nanoscale detector offers particle detection measurements with unprecendented spatial resolution.","alpha-particle detection; beta-ray detection; particle detectors","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","Quantum Nanoscience","","","",""
"uuid:c61222d3-09c7-478a-ac2a-d3c38e4c47a8","http://resolver.tudelft.nl/uuid:c61222d3-09c7-478a-ac2a-d3c38e4c47a8","Modeling the chemical shift of lanthanide 4f electron binding energies","Dorenbos, P.","","2012","Lanthanides in compounds can adopt the tetravalent [Xe]4fn?1 (like Ce4+, Pr4+, Tb4+), the trivalent [Xe]4fn (all lanthanides), or the divalent [Xe]4f n+1 configuration (like Eu2+, Yb2+, Sm2+, Tm2+). The 4f-electron binding energy depends on the charge Q of the lanthanide ion and its chemical environment A. Experimental data on three environments (i.e., the bare lanthanide ions where A=vacuum, the pure lanthanide metals, and the lanthanides in aqueous solutions) are employed to determine the 4f-electron binding energies in all divalent and trivalent lanthanides. The action of the chemical environment on the 4f-electron binding energy will be represented by an effective ambient charge QA=?Q at an effective distance from the lanthanide. This forms the basis of a model that relates the chemical shift of the 4f-electron binding energy in the divalent lanthanide with that in the trivalent one. Eu will be used as the lanthanide of reference, and special attention is devoted to the 4f-electron binding energy difference between Eu2+ and Eu3+. When that difference is known, the model provides the 4f-electron binding energies of all divalent and all trivalent lanthanide ions relative to the vacuum energy.","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","RRR/Radiation, Radionuclides and Reactors","","","",""
"uuid:a829f639-5a29-4ca7-9216-f9ede04f4dc9","http://resolver.tudelft.nl/uuid:a829f639-5a29-4ca7-9216-f9ede04f4dc9","Quantum interference and manipulation of entanglement in silicon wire waveguide quantum circuits","Bonneau, D.; Engin, E.; Dorenbos, S.N.; Zwiller, V.","","2012","Integrated quantum photonic waveguide circuits are a promising approach to realizing future photonic quantum technologies. Here, we present an integrated photonic quantum technology platform utilizing the silicon-oninsulator material system, where quantum interference and the manipulation of quantum states of light are demonstrated in components orders of magnitude smaller than previous implementations. Two-photon quantum interference is presented in a multi-mode interference coupler, and the manipulation of entanglement is demonstrated in a Mach–Zehnder interferometer, opening the way to an all-silicon photonic quantum technology platform.","","en","journal article","IOP Publishing","","","","","","","","Applied Sciences","Kavli Institute of Nanoscience","","","",""
"uuid:6f343f63-00a3-498c-89d5-dcc1fa4f814e","http://resolver.tudelft.nl/uuid:6f343f63-00a3-498c-89d5-dcc1fa4f814e","Thermoluminescence investigation of donor (Ce3+, Pr3+, Tb3+) acceptor (Eu3+, Yb3+) pairs in Y3Al5O12","You, F.; Bos, A.J.J.; Shi, Q.; Huang, S.; Dorenbos, P.","","2012","The thermoluminescence properties of Y3Al5O12 (YAG) doped with an electron donor lanthanide (Ce3+, Pr3+, or Tb3+) together with an electron acceptor lanthanide (Yb3+ or Eu3+) were studied with the aim to locate the energy levels of each divalent and each trivalent lanthanide within the band gap. The activation energies needed to liberate electrons trapped by Yb3+ or Eu3+ were determined from thermoluminescence heating rate plots. With an automated thermoluminescence excitation spectroscopy technique, information on the energy level location of the electron donors Ce3+, Pr3+, and Tb3+ was obtained. By combining all data with an empirical model, a scheme containing all the divalent and trivalent lanthanide energy levels in YAG has been constructed.","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","RRR/Radiation, Radionuclides and Reactors","","","",""
"uuid:cce107ae-7cbc-4edf-810b-4f05a528b186","http://resolver.tudelft.nl/uuid:cce107ae-7cbc-4edf-810b-4f05a528b186","Energy Dependence of the Relative Light Output of YAlO3:Ce, Y2SiO5:Ce, and YPO4:Ce Scintillators","Khodyuk, I.V.; Rodnyi, P.A.; Dorenbos, P.","","2012","The nonlinear dependence of the relative light output on the energy deposited in single-crystal scintillation materials YAlO3:Ce (YAP:Ce), Y2SiO5:Ce (YSO:Ce), and YPO4:Ce (YPO:Ce) has been studied. The investigations have been conducted under quasi-monochromatic X-ray excitation in the energy range of 9.5–100 keV. In addition to the standard technique for measuring the nonproportional scintillator response based on the dependence of the full-energy peak position on the energy of incident radiation, a method is proposed for measuring the light output by X-ray fluorescence peaks. Using this method for YAP:Ce, it is possible to investigate the nonlinear dependence of the light output on the photon energy in the energy range of 2–40 keV. Along with this method, the K-dip spectroscopy method has been proposed and tested by measuring the dependence of the relative light output on the electron energy in the range of 0.1–80.0 keV. The processes resulting in the loss of the scintillation material efficiency at a high ionization density are considered.","","en","journal article","Springer-Verlag","","","","","","","","Applied Sciences","Radiation, Radionulicdes and Reactors","","","",""
"uuid:ffd251b6-fcf5-46d1-b150-f13e86f39d03","http://resolver.tudelft.nl/uuid:ffd251b6-fcf5-46d1-b150-f13e86f39d03","Longitudinal and transverse exciton-spin relaxation in a single InAsP quantum dot embedded inside a standing InP nanowire using photoluminescence spectroscopy","Sasakura, H.; Hermannstädter, C.; Dorenbos, S.N.; Akopian, N.; Van Kouwen, M.P.; Motohisa, J.; Kobayashi, Y.; Kumano, H.; Kondo, K.; Tomioka, K.; Fukui, T.; Suemune, I.; Zwiller, V.","","2012","We have investigated the optical properties of a single InAsP quantum dot embedded in a standing InP nanowire. Elongation of the transverse exciton-spin relaxation time of the exciton state with decreasing excitation power was observed by first-order photon correlation measurements. This behavior is well explained by the motional narrowing mechanism induced by Gaussian fluctuations of environmental charges in the nanowire. The longitudinal exciton-spin relaxation time is evaluated by the degree of the random polarization of emission originating from exciton states confined in a single-nanowire quantum dot by using Mueller calculus based on Stokes parameters representation. The reduction in the random polarization component with decreasing excitation power is caused by suppression of the exchange interaction of electron and hole due to an optically induced internal electric field by the dipoles at the wurtzite and zinc-blende heterointerfaces in the InP nanowire","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:a2a3d8df-2f7c-4928-a64b-4fa4f62c77fd","http://resolver.tudelft.nl/uuid:a2a3d8df-2f7c-4928-a64b-4fa4f62c77fd","Persistent luminescence in MSi2O2N2:Eu phosphors","Botterman, J.; Van den Eeckhout, K.; Bos, A.J.J.; Dorenbos, P.; Smet, P.F.","","2012","In this work we study the persistent luminescence properties of europium-doped alkaline earth silicon oxynitrides (CaSi2O2N2, SrSi2O2N2 and BaSi2O2N2). All compounds show afterglow emission, with an emission spectrum which is similar to the steady state photoluminescence. The afterglow decay time for BaSi2O2N2:Eu and SrSi2O2N2:Eu is about 50 and 100 minutes respectively, while for CaSi2O2N2:Eu the afterglow intensity is very low. Although the persistent luminescence can be induced by ultraviolet light (250-300 nm) in all three phosphors, only for BaSi2O2N2:Eu low energy radiation (350-500 nm) allows filling of the traps responsible for the afterglow.","optical storage materials; rare-earth-doped materials; spectroscopy, fluorescence and luminescence; fluorescent and luminescent materials; photoluminescence","en","journal article","Optical Society of America","","","","","","","","Applied Sciences","RRR/Radiation, Radionuclides and Reactors","","","",""
"uuid:994b7abe-c002-4698-995c-e2b699259667","http://resolver.tudelft.nl/uuid:994b7abe-c002-4698-995c-e2b699259667","Fast Path and Polarization Manipulation of Telecom Wavelength Single Photons in Lithium Niobate Waveguide Devices","Bonneau, D.; Lobino, M.; Jiang, P.; Natarajan, C.M.; Tanner, M.G.; Hadfield, R.H.; Dorenbos, S.N.; Zwiller, V.; Thompson, M.G.; O'Brien, J.L.","","2012","We demonstrate fast polarization and path control of photons at 1550 nm in lithium niobate waveguide devices using the electro-optic effect. We show heralded single photon state engineering, quantum interference, fast state preparation of two entangled photons, and feedback control of quantum interference. These results point the way to a single platform that will enable the integration of nonlinear single photon sources and fast reconfigurable circuits for future photonic quantum information science and technology.","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:1a7741c0-5bd0-4e77-a679-cb77c9307c11","http://resolver.tudelft.nl/uuid:1a7741c0-5bd0-4e77-a679-cb77c9307c11","Ultraviolet-vacuum ultraviolet photoluminescence and x ray radioluminescence of Ce3+-doped Ba3MgSi2O8","Ding, X.; Liang, H.; Hou, D.; Su, Q.; Dorenbos, P.; Sun, S.; Tao, Y.","","2011","Ce3+-doped Ba3MgSi2O8 phosphors were prepared by a solid-state reaction route. The photoluminescence properties in the vacuum ultraviolet-vis spectral range and the x ray excited radioluminescence were investigated. Ce3+ ions were found to enter three different sites in the host lattice. Five excitation bands and two emission bands of Ce(1)3+ centers were observed in the spectra. For Ce(2)3+ and Ce(3)3+ centers, the lowest 5d excitation bands and the emission bands were determined. The light yields of samples under x ray excitation were estimated by comparing the integrated emission intensities of our samples with that of BaF2.","barium compounds; cerium; colour centres; magnesium compounds; phosphors; photoluminescence","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","RRR/Radiation, Radionuclides and Reactors","","","",""
"uuid:299142bc-2b72-47ce-b8da-b59e8c4c2834","http://resolver.tudelft.nl/uuid:299142bc-2b72-47ce-b8da-b59e8c4c2834","Generation of degenerate, factorizable, pulsed squeezed light at telecom wavelengths","Gerrits, T.; Stevens, M.J.; Baek, B.; Calkins, B.; Lita, A.; Glancy, S.; Knill, E.; Nam, S.W.; Mirin, R.P.; Hadfield, R.H.; Bennink, R.S.; Grice, W.P.; Dorenbos, S.N.; Zijlstra, T.; Klapwijk, T.M.; Zwiller, V.","","2011","We characterize a periodically poled KTP crystal that produces an entangled, two-mode, squeezed state with orthogonal polarizations, nearly identical, factorizable frequency modes, and few photons in unwanted frequency modes. We focus the pump beam to create a nearly circular joint spectral probability distribution between the two modes. After disentangling the two modes, we observe Hong-Ou-Mandel interference with a raw (background corrected) visibility of 86% (95%) when an 8.6 nm bandwidth spectral filter is applied. We measure second order photon correlations of the entangled and disentangled squeezed states with both superconducting nanowire single-photon detectors and photon-number-resolving transition-edge sensors. Both methods agree and verify that the detected modes contain the desired photon number distributions","quantum optics; photon statistics; quantum detectors; squeezed states; quantum information and processing","en","journal article","Optical Society of America","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:1d60880f-345e-4634-b236-2f24c29a0df4","http://resolver.tudelft.nl/uuid:1d60880f-345e-4634-b236-2f24c29a0df4","Superconducting Single Photon Detectors","Dorenbos, S.N.","Kouwenhoven, L.P. (promotor)","2011","This thesis is about the development of a detector for single photons, particles of light. New techniques are being developed that require high performance single photon detection, such as quantum cryptography, single molecule detection, optical radar, ballistic imaging, circuit testing and fluorescence spectroscopy. Superconducting single photon detectors (SSPDs) are sensitive to single photons from the ultraviolet to the near infrared. In this thesis steps has been taken towards improving this type of detectors and implementing them in experiments. We have fabricated SSPDs in the Van Leeuwenhoek Laboratory at the TU Delft from NbTiN on an oxidized silicon substrate and we show world record system detection efficiencies at telecommunication wavelengths. In addtition, we have adjusted the geometry to get rid of the polarization dependence of the quantum efficiency. SSPDs fabricated from a new material show enhanced efficiency at longer wavelengths. Different read out schemes can scale a single pixel to an array of detectors. We have proven by implementing the SSPDs in a Hanbury-Brown Twiss setup that nanowire quantum dots emit single photons. We also have demonstrated that SSPDs are sensitive to single surface plasmon polaritons and single electrons.","Superconducting Single Photon Detectors","en","doctoral thesis","","","","","","","","","Applied Sciences","Applied Physics","","","",""
"uuid:4324a884-ca20-4ea5-9233-45b39a795e1b","http://resolver.tudelft.nl/uuid:4324a884-ca20-4ea5-9233-45b39a795e1b","Systematics in the optical and electronic properties of the binary lanthanide halide, chalcogenide and pnictide compounds: An overview","Rogers, E.G.; Dorenbos, P.; Van der Kolk, E.","","2011","The basic optical, electrical and chemical properties of the binary divalent, trivalent and tetravalent lanthanide (Ln = La, . . . , Lu) halides (F, Cl, Br and I), chalcogenides (O, S, Se and Te) and pnictides (N, P, As and Sb) were studied using an empirical model that utilizes the systematic behaviour in the energy difference between the localized 4f n-states, the 5d-derived conduction band and the mp-derived valence band (m = 2, . . . , 5) over the Lanthanide series. As the wide variety in the electrical and optical properties of Ln materials is to a large extent controlled by the energy of these states relative to each other, it is possible to simultaneously predict insulating, semiconducting or metallic behaviour, the nature and magnitude of bandgap energies and the chemical stability of Ln materials as well as valence and valence changes of Ln ions. It can thus be used to predict the basic electronic structure of materials for which no experimental data can be found, and may be a guideline for theoretical modelling.","","en","journal article","IOP Publishing","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:adafbc72-36aa-447f-8da1-73648590d695","http://resolver.tudelft.nl/uuid:adafbc72-36aa-447f-8da1-73648590d695","Correlated photon-pair generation in a periodically poled MgO doped stoichiometric lithium tantalate reverse proton exchanged waveguide","Lobino, M.; Marshall, G.D.; Xiong, C.; Clark, A.S.; Bonneau, D.; Natarajan, C.M.; Tanner, M.G.; Hadfield, R.H.; Dorenbos, S.N.; Zijlstra, T.; Zwiller, V.; Marangoni, M.; Ramponi, R.; Thompson, M.G.; Eggleton, B.J.; O'Brien, J.L.","","2011","We demonstrate photon-pair generation in a reverse proton exchanged waveguide fabricated on a periodically poled magnesium doped stoichiometric lithium tantalate substrate. Detected pairs are generated via a cascaded second order nonlinear process where a pump laser at wavelength of 1.55 ?m is first doubled in frequency by second harmonic generation and subsequently downconverted around the same spectral region. Pairs are detected at a rate of 42/s with a coincidence to accidental ratio of 0.7. This cascaded pair generation process is similar to four-wave-mixing where two pump photons annihilate and create a correlated photon pair.","ion exchange; lithium compounds; magnesium compounds; multiwave mixing; optical fabrication; optical harmonic generation; optical pumping; optical waveguides; stoichiometry; two-photon processes","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:3899f042-8517-43b7-b03f-45b3c631bfe6","http://resolver.tudelft.nl/uuid:3899f042-8517-43b7-b03f-45b3c631bfe6","Read-out of superconducting single photon detectors","Dorenbos, S.N.; Zwiller, V.G.; Schouten, R.N.","","2011","Detection arrangement having an array of at least one superconducting single photon detector (SSPD). The detection arrangement further has a cryogenic part (9) with the array of at least one SSPD (1), the cryogenic part (9) being at a superconducting temperature in operation. Also, a separate charge storage element (5) in the form of an electronic component, is provided which is connected to an output terminal (3) of each of the at least one SSPD (1). The separate charge storage elements (5) are positioned on the cryogenic part (9).","","en","patent","European Patent Office","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:709f8f6b-e04b-4131-b9c5-824475869421","http://resolver.tudelft.nl/uuid:709f8f6b-e04b-4131-b9c5-824475869421","Erratum: “Generation of correlated photon pairs in a chalcogenide As2S3 waveguide” [ Appl. Phys. Lett. 98, 051101 (2011) ]","Xiong, C.; Marshall, G.D.; Peruzzo, A.; Lobino, M.; Clark, A.S.; Choi, D.Y.; Madden, S.J.; Natarajan, C.M.; Tanner, M.G.; Hadfield, R.H.; Dorenbos, S.N.; Zijlstra, T.; Zwiller, V.; Thompson, M.G.; Rarity, J.G.; Steel, M.J.; Luther-Davies, B.; Eggleton, B.J.; O'Brien, J.L.","","2011","","arsenic compounds; optical waveguides; sulphur compounds","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:2d270a4b-c0ee-4e69-a736-0afb3634e64c","http://resolver.tudelft.nl/uuid:2d270a4b-c0ee-4e69-a736-0afb3634e64c","Generation of correlated photon pairs in a chalcogenide As2S3 waveguide","Xiong, C.; Marshall, G.D.; Peruzzo, A.; Lobino, M.; Clark, A.S.; Choi, D.Y.; Madden, S.J.; Natarajan, C.M.; Tanner, M.G.; Hadfield, R.H.; Dorenbos, S.N.; Zijlstra, T.; Zwiller, V.; Thompson, M.G.; Rarity, J.G.; Steel, M.J.; Luther-Davies, B.; Eggleton, B.J.; O'Brien, J.L.","","2011","We demonstrate a 1550 nm correlated photon-pair source in an integrated glass platform—a chalcogenide As2S3 waveguide. A measured pair coincidence rate of 80?s?1 was achieved using 57 mW of continuous-wave pump. The coincidence to accidental ratio was shown to be limited by spontaneous Raman scattering effects that are expected to be mitigated by using a pulsed pump source.","arsenic compounds; chalcogenide glasses; optical pumping; optical waveguides; quantum optics; Raman spectra; sulphur compounds","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:5436a300-f850-41e7-963a-b5396aa66eed","http://resolver.tudelft.nl/uuid:5436a300-f850-41e7-963a-b5396aa66eed","Carrier recombination processes and divalent lanthanide spectroscopy in YPO4:Ce3+;L3+ (L=Sm,Dy,Tm)","Dorenbos, P.; Bos, A.J.J.; Poolton, N.R.J.","","2010","We studied charge carrier trapping, detrapping, and recombination phenomena in Ce3+ doped YPO4, codoped with Sm3+, Dy3+, or Tm3+. Ce ions trap the holes and Sm, Dy, and Tm trap electrons created during x-ray irradiation. By means of red to infrared stimulation, the trapped electrons can be back transferred to Ce leading to shorter wavelength Ce3+?5d-4f luminescence. Excitation spectra for this recombination luminescence were recorded from 10 K to room temperature. It provides information on the excited state energies of divalent Sm, Dy, and Tm with respect to the lanthanide ground state energy and with respect to the mobility edge energy of YPO4. From the temperature dependence, insight is obtained on the carrier recombination pathways. We will identify temperature independent tunneling recombination, recombination by thermal excitation to the conduction band, and phonon-assisted delocalization of electrons from impurity states within the conduction band.","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:8bdee205-c805-40e2-8fed-552a80a54775","http://resolver.tudelft.nl/uuid:8bdee205-c805-40e2-8fed-552a80a54775","Nonproportional response of LaBr3:Ce and LaCl3:Ce scintillators to synchrotron x-ray irradiation","Khodyuk, I.V.; Dorenbos, P.","","2010","The nonproportional scintillation response of LaBr3 doped with 5% Ce3+ and of LaCl3 doped with 10% Ce3+ was measured using highly monochromatic synchrotron irradiation. To estimate the photon response, pulse height spectra at many finely spaced energy values between 9 and 100 keV were measured. The experiment was carried out at the X-1 beamline at the Hamburger Synhrotronstrahlungslabor (HASYLAB) synchrotron radiation facility in Hamburg, Germany. Special attention was paid to the x-ray fluorescence escape peaks as they provide us with additional information about photon response in the range 1.2–14.5 keV for LaBr3:Ce and 2.0–11.6 keV for LaCl3:Ce. A rapid variation of the photon response curve is observed near the lanthanum K-electron binding energy for both scintillators. A dense sampling of data was performed around this energy and those data are used to apply a method, which we call K-dip spectroscopy. This method allows us to derive the electron response curves of LaBr3:Ce and LaCl3:Ce down to energies as low as 0.1 keV.","","en","journal article","Institute of Physics","","","","","","","","Applied Sciences","Luminescence Materials Research Group","","","",""
"uuid:893decd4-b0f4-425c-82d7-41368a5fd01c","http://resolver.tudelft.nl/uuid:893decd4-b0f4-425c-82d7-41368a5fd01c","A high efficiency superconducting nanowire single electron detector","Rosticher, M.; Ladan, F.R.; Maneval, J.P.; Dorenbos, S.N.; Zijlstra, T.; Klapwijk, T.M.; Zwiller, V.; Lupa?cu, A.; Nogues, G.","","2010","We report the detection of single electrons using a Nb0.7Ti0.3N superconducting wire deposited on an oxidized silicon substrate. While it is known that this device is sensitive to single photons, we show that it also detects single electrons with kilo-electron-volt energy emitted from the cathode of a scanning electron microscope with an efficiency approaching unity. The electron and photon detection efficiency map of the same device are in good agreement. We also observe detection events outside the active area of the device, which we attribute to sensitivity to backscattered electrons.","cathodes; electron backscattering; nanowires; photon counting; scanning electron microscopy; superconducting photodetectors","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:c0b2de25-676c-46ab-ab34-17dfba84c4d9","http://resolver.tudelft.nl/uuid:c0b2de25-676c-46ab-ab34-17dfba84c4d9","Position controlled nanowires for infrared single photon emission","Dorenbos, S.N.; Sasakura, H.; Van Kouwen, M.P.; Akopian, N.; Adachi, S.; Namekata, N.; Jo, M.; Motohisa, J.; Kobayashi, Y.; Tomioka, K.; Fukui, T.; Inoue, S.; Kumano, H.; Natarajan, C.M.; Hadfield, R.H.; Zijlstra, T.; Klapwijk, T.M.; Zwiller, V.; Suemune, I.","","2010","We report the experimental demonstration of single-photon and cascaded photon pair emission in the infrared, originating from a single InAsP quantum dot embedded in a standing InP nanowire. A regular array of nanowires is fabricated by epitaxial growth on an electron-beam patterned substrate. Photoluminescence spectra taken on single quantum dots show narrow emission lines. Superconducting single photon detectors, which have a higher sensitivity than avalanche photodiodes in the infrared, enable us to measure auto and cross correlations. Clear antibunching is observed [g(2)(0) = 0.12] and we show a biexciton–exciton cascade, which can be used to create entangled photon pairs.","biexcitons; epitaxial growth; excitons; III-V semiconductors; indium compounds; infrared spectra; nanofabrication; nanowires; photoluminescence; semiconductor growth; semiconductor quantum dots; semiconductor quantum wires","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:858534fe-7e68-49a3-8d67-a47a955ec82d","http://resolver.tudelft.nl/uuid:858534fe-7e68-49a3-8d67-a47a955ec82d","Luminescence of Ce3+ at two different sites in ?-Sr2P2O7 under vacuum ultraviolet-UV and x-ray excitation","Hou, D.; Han, B.; Chen, W.; Liang, H.; Su, Q.; Dorenbos, P.; Huang, Y.; Gao, Z.; Tao, Y.","","2010","A series of Ce3+ doped ?-Sr2?2xCexNaxP2O7 phosphor compounds has been prepared using a high-temperature solid-state reaction technique. The luminescence properties under vacuum ultraviolet-UV and x-ray excitation were studied. Luminescence spectra reveal three UV-emitting peaks at about 310, 330, and 350 nm from which we conclude that Ce3+ occupies two distinct sites in ?-Sr2P2O7. The influences of the doping concentration, the temperature, and the excitation wavelength on the luminescence of Ce3+ at the Ce(I) and Ce(II) sites together with the decay characteristics are discussed. The light yield under x-ray excitation is found to be around 10?000 photons/MeV.","cerium; cerium compounds; doping profiles; luminescence; phosphors; sodium compounds; strontium compounds; ultraviolet radiation effects; X-ray effects","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","RRR/Radiation, Radionuclides and Reactors","","","",""
"uuid:7188a6cc-a324-4657-88b0-414cef09d7bd","http://resolver.tudelft.nl/uuid:7188a6cc-a324-4657-88b0-414cef09d7bd","Enhanced telecom wavelength single-photon detection with NbTiN superconducting nanowires on oxidized silicon","Tanner, M.G.; Natarajan, C.M.; Pottapenjara, V.K.; O'Connor, J.A.; Warburton, R.J.; Hadfield, R.H.; Baek, B.; Nam, S.; Dorenbos, S.N.; Bermúdez Ureña, E.; Zijlstra, T.; Klapwijk, T.M.; Zwiller, V.","","2010","Superconducting nanowire single-photon detectors (SNSPDs) have emerged as a highly promising infrared single-photon detector technology. Next-generation devices are being developed with enhanced detection efficiency (DE) at key technological wavelengths via the use of optical cavities. Furthermore, new materials and substrates are being explored for improved fabrication versatility, higher DE, and lower dark counts. We report on the practical performance of packaged NbTiN SNSPDs fabricated on oxidized silicon substrates in the wavelength range from 830 to 1700 nm. We exploit constructive interference from the SiO2/Si interface in order to achieve enhanced front-side fiber-coupled DE of 23.2 % at 1310 nm, at 1 kHz dark count rate, with 60 ps full width half maximum timing jitter.","infrared detectors; nanowires; niobium compounds; superconducting photodetectors; timing jitter; titanium compounds","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","Kavli Institute of Nanoscience","","","",""
"uuid:ac74baa2-c479-4519-90ae-cb28d3842cc5","http://resolver.tudelft.nl/uuid:ac74baa2-c479-4519-90ae-cb28d3842cc5","Nonproportional scintillation response of NaI:Tl to low energy x-ray photons and electrons","Khodyuk, I.V.; Rodnyi, P.A.; Dorenbos, P.","","2010","Nonproportional response of the scintillation yield of NaI:Tl was measured using highly monochromatic synchrotron irradiation ranging from 9–100 keV. Special attention is paid to the x-ray escape peaks. They provide us additional information about photon response in the range 0.9–12 keV. A rapid variation in the photon response curve is observed near the iodine K-electron binding energy. A dense sampling of data is performed around this energy and that data are used to apply a method, which we call K-dip spectroscopy. This method allows us to derive the electron response curve of NaI:Tl down to energies as low as 30 eV. A comparison of our data with data of others employing different methods is made. Advantages, limitations, and peculiarities of presented techniques and methods are discussed.","solid scintillation detectors; X-ray detection","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:fbf231a1-ec29-44b3-82e3-42366934e2f7","http://resolver.tudelft.nl/uuid:fbf231a1-ec29-44b3-82e3-42366934e2f7","Lanthanide 4f-level location in AVO4:Ln3+ (A = La, Gd, Lu) crystals","Krumpel, A.H.; Van der Kolk, E.; Cavalli, E.; Boutinaud, P.; Bettinelli, M.; Dorenbos, P.","","2009","The spectral properties of LaVO4, GdVO4 and LuVO4 crystals doped with Ce3+, Pr3+, Eu3+ or Tb3+ have been investigated in order to determine the position of the energy levels relative to the valence and conduction bands of the hosts along the trivalent and divalent lanthanide series. Pr3+ and Tb3+ ground state levels are positioned based on the electron transfer energy from those states to the conduction band, the so-called intervalence charge transfer (IVCT). This approach is compared with an alternative model that is based on electron transfer from the valence band to a lanthanide.","","en","journal article","Institute of Physics","","","","","","","","Applied Sciences","RRR/Radiation, Radionuclides and Reactors","","","",""
"uuid:334e8cda-c308-4ce0-a070-76af3c754a8b","http://resolver.tudelft.nl/uuid:334e8cda-c308-4ce0-a070-76af3c754a8b","The thermally induced metal–semiconducting phase transition of samarium monosulfide (SmS) thin films","Rogers, E.; Smet, P.F.; Dorenbos, P.; Poelman, D.; Van der Kolk, E.","","2009","High quality phase pure samarium monosulfide (SmS) thin films were prepared by electron beam evaporation using a samarium metal source in a H2S atmosphere. The optical properties (reflection, transmission, absorption) of the films in the semiconducting and metallic phase were analysed from the UV to the mid-IR and explained in terms of the electronic structure of SmS. In this paper it will be shown that metallic SmS thin films exhibit an apparently continuous thermally induced metallic to semiconducting phase transition when studied optically. Temperature dependent x-ray diffraction measurements, however, indicate that the metallic to semiconductor phase transition is in fact first order at a single grain level. The apparently continuous optical behaviour is therefore due to the polycrystalline nature of the films.","","en","journal article","Institute of Physics","","","","","","","","Applied Sciences","","","","",""
"uuid:314cfa87-61b5-4ae4-9982-0160ab507d34","http://resolver.tudelft.nl/uuid:314cfa87-61b5-4ae4-9982-0160ab507d34","Het koude vuur","Dorenbos, P.","","2009","","Intreerede","nl","public lecture","Delft University of Technology","","","","","","","","Applied Sciences","","","","",""
"uuid:14f12e08-ab15-40bb-a2fb-76dda7b2ed15","http://resolver.tudelft.nl/uuid:14f12e08-ab15-40bb-a2fb-76dda7b2ed15","Controlled electron and hole trapping in YPO4:Ce3+,Ln3+ and LuPO4:Ce3+,Ln3+ (Ln=Sm, Dy, Ho, Er, Tm)","Krumpel, A.H.; Bos, A.J.J.; Bessière, A.; Van der Kolk, E.; Dorenbos, P.","","2009","A detailed and systematic electron trapping study was conducted in the scientifically important wide band-gap materials LuPO4 and YPO4 doubly doped with Ce3+ and Ln3+ (Ln=Sm, Dy, Ho, Er, Tm). By using vacuum-ultraviolet luminescence spectroscopy and detailed thermoluminescence spectroscopy it was possible to establish by two independent methods that the observed electron traps can be assigned to the Ln3+ codoping ions. It is shown that the associated electron trap depths are determined by the energy separation between the Ln2+ ground states and the bottom of the conduction band. Both methods reveal a systematic behavior of electron trap depths as a function of the type of Ln3+ codoping ion that can be explained by recently developed empirical models. Small differences in trap depths obtained by the two methods are discussed in the context of charge-transfer induced relaxation processes and uncertainties in glow peak analysis. Our experiments provide valuable information on 4fn?4fn, 4fn?4fn?15d, O2??Ln3+ charge transfer and the lowest-energy PO43? group transitions as well as electron trap depths. These transition energies allowed us to construct a complete energy-level diagram for LuPO4:Ln3+/2+ and YPO4:Ln3+/2+.","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:01ef3192-ce5b-413f-bb74-4ff664ed110b","http://resolver.tudelft.nl/uuid:01ef3192-ce5b-413f-bb74-4ff664ed110b","Impedance model for the polarization-dependent optical absorption of superconducting single-photon detectors","Driessen, E.F.C.; Braakman, F.R.; Reiger, E.M.; Dorenbos, S.N.; Zwiller, V.; De Dood, M.J.A.","","2009","We measured the single-photon detection efficiency of NbN superconducting single-photon detectors as a function of the polarization state of the incident light for different wavelengths in the range from 488 nm to 1550 nm. The polarization contrast varies from ?5% at 488 nm to ?30% at 1550 nm, in good agreement with numerical calculations. We use an optical-impedance model to describe the absorption for polarization parallel to the wires of the detector. For the extremely lossy NbN material, the absorption can be kept constant by keeping the product of layer thickness and filling factor constant. As a consequence, the maximum possible absorption is independent of filling factor. By illuminating the detector through the substrate, an absorption efficiency of ? 70% can be reached for a detector on Si or GaAs, without the need for an optical cavity.","","en","journal article","EDP sciences","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:a98b1e4d-b131-4b3b-9838-32ef699a2e63","http://resolver.tudelft.nl/uuid:a98b1e4d-b131-4b3b-9838-32ef699a2e63","Temperature dependent scintillation properties of pure LaCl3","Bizarri, G.; Dorenbos, P.","","2009","The scintillation yield, scintillation decay, and x-ray excited emission of pure LaCl3 was studied as a function of temperature between 80 and 600 K. Two broad band emissions centered around 325 nm and 400 nm were identified and correlated to emissions from two localized exciton states named STE1 and STE2, respectively. Different temperature dependences were observed for the short and long wavelength band intensity. From 80 to 150 K, the 400 nm band intensity increases at the expense of the 325 nm band intensity. Above 150 K almost all emission is in the 400 nm band. From 150 to 600 K, the intensity of this band decreases and its lifetime shortens. These results are analyzed and interpreted with a model that comprises the creation of STE1 and STE2 self-trapped excitons, thermally activated quenching of STE1 and STE2 emission, and thermally activated transfer of excitation energy from STE1 to STE2.","condensed matter; elec trical; magnetic and optical","en","journal article","Institute of Physics","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:a351de07-93fe-45e5-b0b8-346b09febf24","http://resolver.tudelft.nl/uuid:a351de07-93fe-45e5-b0b8-346b09febf24","Effect of Electron Traps on Scintillation of Praseodymium Activated Lu3Al5O12","Drozdowski, W.; Dorenbos, P.; Drozdowska, R.; Bos, A.J.J.; Poolton, N.R.J.; Tonelli, M.; Alshourbagy, M.","","2009","In this paper we present the studies performed on a set of Lu3Al5O12:Pr (LuAG:Pr) crystals with praseodymium concentration between 1.5 and 10%, grown by the micro-pulling-down (muPD) technique. The research comprises the measurements of X-ray excited emission spectra and 137Cs gamma-ray pulse height spectra in a range from 78 to 600 K, and thermoluminescence glow curves. Based on experimental data we discuss the dependence of scintillation properties of Lu3Al5O12:Pr on praseodymium content and temperature. The main attention is focused on a distinct increase of scintillation yield with temperature, which we attribute to existence of shallow electron traps and their temperature-dependent contribution to scintillation of LuAG:Pr. An active role of traps is demonstrated by a novel experiment combining X-ray and laser excitation.","LuAG:Pr; light yield; scintillation mechanism; trap","en","journal article","IEEE","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:e15ec1b1-03d5-44be-bdee-eceace09ab72","http://resolver.tudelft.nl/uuid:e15ec1b1-03d5-44be-bdee-eceace09ab72","Lanthanide 4f-level location in lanthanide doped and cerium-lanthanide codoped NaLaF4 by photo- and thermoluminescence","Krumpel, A.H.; Van der Kolk, E.; Zeelenberg, D.; Bos, A.J.J.; Krämer, K.W.; Dorenbos, P.","","2008","Photo- and thermoluminescence (TL) spectra of NaLaF4:Ln3+ (Ln = Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm) and NaLaF4:Ce3+, Ln3+ (Ln = Nd,Sm,Ho,Er,Tm) are presented and used together with the empirical Dorenbos model in order to establish the 4f energy level positions of all tri- and divalent lanthanide ions doped in NaLaF4. The information will be presented in the form of an energy level diagram. It is shown that in addition to this diagram only two assumptions, viz., the presence of two host related electron traps and the presence of Vk-centers, are necessary for explaining the lanthanide-specific TL glow curves of both Ln mono- and Ce–Ln codoped NaLaF4.","cerium; dysprosium; electron traps; europium; gadolinium; holmium; neodymium; photoluminescence; praseodymium; samarium; sodium compounds; terbium; thermoluminescence; thulium","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:1bdd29fb-571a-4fa0-becf-deda09706fec","http://resolver.tudelft.nl/uuid:1bdd29fb-571a-4fa0-becf-deda09706fec","Scintillation Properties of Praseodymium Activated Lu3Al5O12 Single Crystals","Drozdowski, W.; Dorenbos, P.; De Haas, J.T.M.; Drozdowska, R.; Owens, A.; Kamada, K.; Tsutsumi, K.; Usuki, Y.; Yanagida, T.; Yoshikawa, A.","","2008","Scintillation properties of LuAG:Pr grown by Furukawa Co. Ltd., Japan, have been studied. The best crystals display light outputs up to 19000 ph/MeV and an energy resolution of 4.6% at 662 keV. The scintillation yield is found to be a function of size and temperature of the sample; it can be enhanced by 40% upon heating to 450 K. Radioluminescence spectra show both - and - transitions of Pr3+ ions; the contribution of the latter increases with temperature. The scintillation decays are complex, with a fast decay constant of 20 ns. The presence of 176Lu induces high background activity.","energy resolution; LuAG; praseodymium; scintillation; yield; scintillator","en","journal article","IEEE","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:66291656-3ff4-4fda-bf74-d2d0ec3d03d2","http://resolver.tudelft.nl/uuid:66291656-3ff4-4fda-bf74-d2d0ec3d03d2","CeBr3 Scintillator Development for Possible Use in Space Missions","Drozdowski, W.; Dorenbos, P.; Bos, A.J.J.; Bizarri, G.; Owens, A.; Quaranti, F.G.A.","","2008","CeBr3 crystals have been studied to assess their utility as potential gamma ray spectrometers for future ESA planetary missions. Pulse height spectra, scintillation time profiles, X-ray excited emission spectra, and photoluminescence spectra have been recorded as a function of temperature between 78 and 600 K. In addition, the influence of exposing CeBr3 to various doses of gamma rays from a strong 60Co source on its scintillation performance has been investigated.","CeBr3; energy resolution; LaBr3:Ce; radiation damage; scintillation yield; scintillator; self-absorption","en","journal article","IEEE","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:d21e9575-db5f-46d1-91b1-6bddd0ea4a48","http://resolver.tudelft.nl/uuid:d21e9575-db5f-46d1-91b1-6bddd0ea4a48","Advances in Yield Calibration of Scintillators","De Haas, J.T.M.; Dorenbos, P.","","2008","By means of a photomultiplier tube, a Si-photodiode, and a Si-avalanche photodiode, the absolute scintillation yield of recently developed LaBr3:Ce, LaCl3:Ce, and (Lu Y)2SiO5:Ce scintillators and traditional Lu2SiO5:Ce, Bi4Ge3O12, NaI:Tl CsI:Tl, and CsI:Na scintillators were determined. These are all well known scintillators that cover emission wavelengths from 250 nm to 750 nm. By comparing the scintillation yield independently measured with the three different photon detectors reliable yield values are obtained.","absolute scintillation yield; gamma detectors; photodiode readout; scintillators","en","journal article","IEEE","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:42942c8d-2bdf-400b-a5e7-69a554154d44","http://resolver.tudelft.nl/uuid:42942c8d-2bdf-400b-a5e7-69a554154d44","Li-Based Thermal Neutron Scintillator Research: Rb2LiYBr6 : Ce3+ and Other Elpasolites","Birowosuto, M.D.; Dorenbos, P.; De Haas, J.T.M.; Van Eijk, C.W.E.; Krämer, K.W.; Güdel, H.U.","","2008","","discrimination; peak resolution; scintillator; thermal neutron","en","journal article","IEEE","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:607f9579-18a2-468d-a561-cfa5b85e6039","http://resolver.tudelft.nl/uuid:607f9579-18a2-468d-a561-cfa5b85e6039","Temperature Dependent Scintillation and Luminescence Characteristics of GdI3: Ce³+","Birowosuto, M.D.; Dorenbos, P.; Bizarri, G.; Van Eijk, C.W.E.; Krämer, K.W.; Güdel, H.U.","","2008","","decay time,; GdI3: Ce3+; light yield; scintillator","en","journal article","IEEE","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:ca5cbb6e-88c0-4a13-8e24-83a9c6dc25dc","http://resolver.tudelft.nl/uuid:ca5cbb6e-88c0-4a13-8e24-83a9c6dc25dc","Ce3+ activated LaBr3?xIx: High-light-yield and fast-response mixed halide scintillators","Birowosuto, M.D.; Dorenbos, P.; Krämer, K.W.; Güdel, H.U.","","2008","Here, we report the scintillation properties of LaBr3?xIx:5%Ce3+ with four different compositions of x, i.e., x = 0.75, 1.5, 2, and 2.25. Radioluminescence spectra reveal a shift of the emission wavelength with the LaBr3 to LaI3 ratio. LaBr1.5I1.5:5%Ce3+ shows the highest scintillation light yield of 58?000?photons/MeV, whereas LaBr0.75I2.25:5%Ce3+ shows the fastest scintillation decay time of 12 ns under 662 keV ?-ray excitation. This decay time is faster than that of 16 ns in LaBr3:Ce3+. The temperature dependence of radioluminescence spectra is presented. The structures and lattice parameters of the materials were determined from powder x-ray diffraction.","cerium; gamma-ray effects; lanthanum compounds; lattice constants; luminescence; scintillation; X-ray diffraction","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:a8560098-ce6a-4ac0-9a40-329777dab1d0","http://resolver.tudelft.nl/uuid:a8560098-ce6a-4ac0-9a40-329777dab1d0","High-resolution luminescence spectroscopy study of down-conversion routes in NaGdF4:Nd3+ and NaGdF4:Tm3+ using synchrotron radiation","Van der Kolk, E.; Dorenbos, P.; Krämer, K.; Biner, D.; Güdel, H.U.","","2008","","excited states; gadolinium compounds,; neodymium; phosphors; photoluminescence; sodium compounds; thulium; two-photon processes","en","journal article","American Physical Society","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:7117c481-815e-4347-85ba-3c11143629fa","http://resolver.tudelft.nl/uuid:7117c481-815e-4347-85ba-3c11143629fa","Cerium-doped barium halide scintillators for x-ray and ?-ray detections","Selling, J.; Schweizer, S.; Birowosuto, M.D.; Dorenbos, P.","","2007","Single crystals of Ce-activated BaCl2, BaBr2, and BaI2 were investigated under x-ray and ?-ray excitation. The Ce3+-related x-ray excited luminescence in BaBr2 shifts significantly to longer wavelengths upon increasing the doping level from 0.1% to 1%. In Ce-activated BaCl2 only a slight shift can be observed. BaI2 does not show any Ce3+-related emission. Scintillation decay time measurements show that the decay in BaBr2 is delayed due to migration processes. Additional K doping has a large influence on the scintillation decay time properties but not on the overall efficiency.","barium compounds; cerium; doping; gamma-ray detection; photoluminescence; scintillation; solid scintillation detectors; X-ray detection","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:83e9f2ab-9fcb-4313-8888-21c2f8255df9","http://resolver.tudelft.nl/uuid:83e9f2ab-9fcb-4313-8888-21c2f8255df9","Vacuum ultraviolet-ultraviolet and x-ray excited luminescence properties of Ba3Gd(BO3)3:Ce3+","Han, B.; Liang, H.; Lin, H.; Zhong, J.; Su, Q.; Dorenbos, P.; Birowosuto, M.D.; Zhang, G.; Fu, Y.","","2007","The phosphors Ba3Gd(BO3)3:Ce3+ were prepared by a solid-state reaction technique at high temperature. The vacuum ultraviolet-ultraviolet and visible spectroscopic properties of the phosphors together with decay time curves are investigated and discussed. The spectroscopic properties are explained by occupancy of Ce3+ at two different Gd sites in the host lattice. The x-ray excited emission spectra of Ba3Gd(BO3)3:Ce3+ were studied and the number of photons emitted per unit of absorbed x-ray energy was calculated. The yield is rather poor and Ba3Gd(BO3)3:Ce3+ appears not a suitable x-ray phosphor.","cerium; barium compounds; gadolinium compounds; phosphors; high-temperature effects; ultraviolet spectra; visible spectra; X-ray spectra; photoluminescence; radiative lifetimes; photons","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:2c006c52-6cba-44ce-8b64-f4876574d9a8","http://resolver.tudelft.nl/uuid:2c006c52-6cba-44ce-8b64-f4876574d9a8","Fiber-coupled NbN superconducting single-photon detectors for quantum correlation measurements","Slysz, W.; Wegrzecki, M.; Bar, J.; Grabiec, P.; Gorska, M.; Reiger, E.; Dorenbos, S.; Zwiller, V.; Milostnaya, I.; Minaeva, O.","","2007","We have fabricated fiber-coupled superconducting single-photon detectors (SSPDs), designed for quantum-correlationtype experiments. The SSPDs are nanostructured (~100-nm wide and 4-nm thick) NbN superconducting meandering stripes, operated in the 2 to 4.2 K temperature range, and known for ultrafast and efficient detection of visible to nearinfrared photons with almost negligible dark counts. Our latest devices are pigtailed structures with coupling between the SSPD structure and a single-mode optical fiber achieved using a micromechanical photoresist ring placed directly over the meander. The above arrangement withstands repetitive thermal cycling between liquid helium and room temperature, and we can reach the coupling efficiency of up to ~33%. The system quantum efficiency, measured as the ratio of the photons counted by SSPD to the total number of photons coupled into the fiber, in our early devices was found to be around 0.3 % and 1% for 1.55 ?m and 0.9 ?m photon wavelengths, respectively. The photon counting rate exceeded 250 MHz. The receiver with two SSPDs, each individually biased, was placed inside a transport, 60-liter liquid helium Dewar, assuring uninterrupted operation for over 2 months. Since the receiver's optical and electrical connections are at room temperature, the set-up is suitable for any applications, where single-photon counting capability and fast count rates are desired. In our case, it was implemented for photon correlation experiments. The receiver response time, measured as a second-order photon cross-correlation function, was found to be below 400 ps, with timing jitter of less than 40 ps.","superconducting single photon detectors; single photon detectors; fiber-coupled optical detectors; quantum correlations; superconducting devices","en","conference paper","SPIE","","","","","","","","Applied Sciences","Kavli Institute of Nanoscience","","","",""
"uuid:552dd9da-1f1c-4667-b10e-c4e1aab3aafc","http://resolver.tudelft.nl/uuid:552dd9da-1f1c-4667-b10e-c4e1aab3aafc","Luminescence quenching by photoionization and electron transport in a LaAlO3:Ce3+ crystal","Van der Kolk, E.; De Haas, J.T.M.; Bos, A.J.J.; Van Eijk, C.W.E.; Dorenbos, P.","","2007","A combined photoconductivity, absorption, and thermoluminescence study was performed to understand the absence of luminescence from Ce3+ in LaAlO3:Ce3+. It is demonstrated that the absence of luminescence is the result of Ce3+ ionization from the 5d excited states, which are all located in the conduction band. Ce3+ ionization is accompanied by the formation of several broad absorption and photoconductivity bands, which are assigned to electron traps. A time and temperature dependent optical investigation of these traps reveals the conditions under which electrons are transferred from Ce3+ to traps and vice versa, from traps back to Ce4+. The observed difference in energy needed to thermally or optically release electrons from traps is qualitatively explained in terms of the location of the ground and excited states of the electron traps with respect to the conduction band.","lanthanum compounds; cerium; photoconductivity; thermoluminescence; impurity absorption spectra; electron traps; conduction bands; photoionisation","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:2b2db179-5ad8-4a8c-a26a-c6772cccfdb3","http://resolver.tudelft.nl/uuid:2b2db179-5ad8-4a8c-a26a-c6772cccfdb3","Thermal-neutron scintillator: Ce3+ activated Rb2LiYBr6","Birowosuto, M.D.; Dorenbos, P.; De Haas, J.T.M.; Van Eijk, C.W.E.; Krämer, K.W.; Güdel, H.U.","","2007","Scintillation and luminescence characteristics of Rb2LiYBr6 doped with 0.1%, 0.5%, 1%, and 5%?Ce3+ are presented. Under optical and x-ray excitation, Ce3+ doublet emission is observed at 385 and 420 nm. Rb2LiYBr6:0.5%?Ce3+ shows very high thermal neutron scintillation light output of 83?000 photons/neutron. An excellent neutron peak resolution of 3.6% (full width at half maximum over peak position) is observed for the 4.8 MeV neutron-reaction products energy response in Rb2LiYBr6:0.1%?Ce3+. This peak shows up at 3.6 MeV ?-equivalent energy and therefore it gives an ?/? ratio of 0.74. The combination of a large fraction of neutron absorption in natural i?(62%), a sharp neutron response peak, high light yield, and large ?/? ratio makes Rb2LiYBr6:Ce3+ an efficient scintillator for thermal neutron detection.","rubidium compounds; lithium compounds; yttrium compounds; scintillation; scintillation counters; luminescence; cerium; neutron detection","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:d590fe4c-39b5-4331-a4a9-f410e4da856d","http://resolver.tudelft.nl/uuid:d590fe4c-39b5-4331-a4a9-f410e4da856d","Systematic and material independent variation of electrical, optical, and chemical properties of Ln-materials over the Ln-series (Ln=La,Ce,Pr,..,Lu)","Van der Kolk, E.; Dorenbos, P.","","2007","A model is presented that successfully predicts electro-optical properties of Lanthanide materials, irrespective whether these materials are inorganic or organic, diluted or concentrated, metallic, semi-conducting or insulating. The model is firmly based on recent experimental data revealing that the variation in 4f and 5d energies relative to the valence band over the Ln series (La, Ce, Pr,.. ,Lu) is universal. Application to LnS and the oxides LnO, Ln2O3 and LnO2 demonstrates its potential by correctly predicting the ground state electron configuration, metallic, insulating or semi-conducting behavior, Ln ion valence state and band-gap of these model Ln systems.","","en","conference paper","SPIE","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:dd5050eb-657e-41f6-aeb0-1b86048f09db","http://resolver.tudelft.nl/uuid:dd5050eb-657e-41f6-aeb0-1b86048f09db","Lanthanide impurity level location in GaN, AlN, and ZnO","Dorenbos, P.; Van der Kolk, E.","","2007","A method that has proven succesful in locating the energy levels of divalent and trivalent lanthanide ions (Ce, Pr,..., Eu,...Yb, Lu) in wide band gap inorganic compounds like YPO4 and CaF2 is applied to locate lanthanide levels in the wideband semiconductors GaN, AlN, their solid solutions AlxGa1-xN, and ZnO. The proposed schemes provide a description of relevant optical and luminescence properties of these lanthanide doped semiconductors. Especially, the relation between thermal quenching of Tb3+ emission and the location of the energy levels is explained.","GaN; AIN; ZnO; lanthanides; localized states","en","conference paper","SPIE","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:ce7ff454-c9d6-4ac3-bb7d-ff98f01f29c8","http://resolver.tudelft.nl/uuid:ce7ff454-c9d6-4ac3-bb7d-ff98f01f29c8","Europium-doped barium halide scintillators for x-ray and ?-ray detections","Selling, J.; Birowosuto, M.D.; Dorenbos, P.; Schweizer, S.","","2007","Single crystals of undoped or europium-doped barium chloride, bromide, and iodide were investigated under x-ray and ?-ray excitations. The Eu2+-related x-ray excited luminescence found in the Eu-doped barium halides occurs at 402, 404, and 425?nm for the chloride, bromide, and iodide, respectively. BaCl2:Eu2+ shows the best scintillation properties of the systems investigated. The light yield is about 20?000±2000?photons?per?MeV of absorbed ?-ray energy, the energy resolution for the 662?keV photopeak is 8.8%±0.9%, and the scintillation decay time is 390±40?ns.","","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:20b365c6-9121-4d9a-9ef7-fe31d86daf30","http://resolver.tudelft.nl/uuid:20b365c6-9121-4d9a-9ef7-fe31d86daf30","Charge carrier and exciton dynamics in LaBr3:Ce3+ scintillators: Experiment and model","Bizarri, G.; Dorenbos, P.","","2007","","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","","","","",""
"uuid:06ca1851-89b6-49cc-99ae-9c164409427d","http://resolver.tudelft.nl/uuid:06ca1851-89b6-49cc-99ae-9c164409427d","Luminescence and site occupancy of Ce3+ in Ba2Ca(BO3)2","Lin, H.; Liang, H.; Han, B.; Zhong, J.; Su, Q.; Dorenbos, P.; Birowosuto, M.D.; Zhang, G.; Fu, Y.; Wu, W.","","2007","","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","","","","",""
"uuid:a172f9e3-3bc9-4fda-8908-7dc49aa444e6","http://resolver.tudelft.nl/uuid:a172f9e3-3bc9-4fda-8908-7dc49aa444e6","Thermal quenching of Ce3+ emission in PrX3 (X = Cl, Br) by intervalence charge transfer","Birowosuto, M.D.; Dorenbos, P.; Van Eijk, C.W.E.; Krämer, K.W.; Güdel, H.U.","","2007","","","en","journal article","IOP","","","","","","","","Applied Sciences","","","","",""
"uuid:eafeffd6-2926-4488-bcd2-2dc001721899","http://resolver.tudelft.nl/uuid:eafeffd6-2926-4488-bcd2-2dc001721899","Lattice relaxation study of the 4f-5d excitation of Ce3+-doped LaCl3, LaBr3, and NaLaF4: Stokes shift by pseudo Jahn-Teller effect","Andriessen, J.; van der Kolk, E.; Dorenbos, P.","","2007","","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","","","","",""
"uuid:4200db54-ceff-4003-aa76-8525f3b43bed","http://resolver.tudelft.nl/uuid:4200db54-ceff-4003-aa76-8525f3b43bed","Location of lanthanide impurity levels in the III-V semiconductor GaN","Dorenbos, P.; Van der Kolk, E.","","2006","Knowledge from lanthanide spectroscopy on wide band gap (6–10?eV) inorganic compounds is used to understand and predict optical and electronic properties of the lanthanides in the III-V semiconductor GaN. For the first time the location of the 4fn ground state energy of each divalent and trivalent lanthanide ion relative to the valence and conduction bands in GaN is presented. The authors will demonstrate that the quantum efficiency of luminescence from Pr3+, Eu3+, Tb3+, and Yb3+ depends on the location of the lanthanide levels. Level location also controls electron acceptor and electron donor properties of lanthanide ions.","gallium compounds; III-V semiconductors; wide band gap semiconductors; impurity states; ground states; valence bands; conduction bands; photoluminescence; praseodymium; europium; terbium; ytterbium","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:14900833-bdb6-4e9e-a41b-07b78fee84a7","http://resolver.tudelft.nl/uuid:14900833-bdb6-4e9e-a41b-07b78fee84a7","High-light-output scintillator for photodiode readout: LuI3:Ce3+","Birowosuto, M.D.; Dorenbos, P.; Van Eijk, C.W.E.; Krämer, K.W.; Güdel, H.U.","","2006","In this paper, we investigated the scintillation properties of LuI3:Ce3+. Radioluminescence, light output, energy resolution, and ?-scintillation decay are reported. We find an extremely high light output of 98?000±10?000?photons/MeV. LuI3:Ce3+ also gives a very high electron-hole (e-h) pair response when it is coupled with an avalanche photodiode (APD) (92?000±9000?e?h?pairs?MeV). With an APD, a best energy resolution (full width at half maximum over the peak position) of 3.3%±0.3% for 662?keV ? quanta is observed. A combination of an extremely high light output and a good energy resolution makes LuI3:Ce3+ an ideal scintillator for radiation sensor applications. Some drawbacks due to the hygroscopicity and the difficult growth of LuI3:Ce3+ crystals are also discussed.","scintillation; lutetium compounds; cerium; photoluminescence; optical materials; avalanche photodiodes","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","Radiation, Radionuclides and Reactors","","","",""
"uuid:e25343fa-36ab-4ee6-a5e3-69130b31c5be","http://resolver.tudelft.nl/uuid:e25343fa-36ab-4ee6-a5e3-69130b31c5be","Scintillation properties and anomalous Ce3+ emission of Cs2NaREBr6:Ce3+ (RE = La,Y,Lu)","Birowosuto, M.D.; Dorenbos, P.; Van Eijk, C.W.E.; Krämer, K.W.; Güdel, H.U.","","2006","","","en","journal article","IOP","","","","","","","","Applied Sciences","","","","",""
"uuid:086210bf-acc2-4ff6-b204-5da74d5d6c3b","http://resolver.tudelft.nl/uuid:086210bf-acc2-4ff6-b204-5da74d5d6c3b","Luminescence of Ce3+ activated fluoro-apatites M5(PO4)3F (M = Ca, Sr, Ba) under VUV—UV and x-ray excitation","Zeng, Q.; Liang, H.; Zhang, G.; Birowosuto, M.D.; Tian, Z.; Lin, H.; Fu, Y.; Dorenbos, P.; Su, Q.","","2006","","","en","journal article","IOP","","","","","","","","Applied Sciences","","","","",""
"uuid:3ed35ea4-a14a-4534-a80c-c1df6380c3c2","http://resolver.tudelft.nl/uuid:3ed35ea4-a14a-4534-a80c-c1df6380c3c2","Lanthanide level location and charge carrier trapping in LiLnSiO4:Ce3+,Sm3+, Ln = Y or Lu","Sidorenko, A.V.; Dorenbos, P.; Bos, A.J.J.; Van Eijk, C.W.E.; Rodnyi, P.A.","","2006","","","en","journal article","IOP","","","","","","","","Applied Sciences","","","","",""
"uuid:055bbf6e-0bc6-43ec-919c-4362a279ab2e","http://resolver.tudelft.nl/uuid:055bbf6e-0bc6-43ec-919c-4362a279ab2e","Scintillation properties of O 1/spl times/1 Inch/sup 3/ LaBr/sub 3/: 5%Ce/sup 3+/ crystal","Bizarri, G.; De Haas, J.T.M.; Dorenbos, P.; Van Eijk, C.W.E.","","2006","","","en","journal article","IEEE","","","","","","","","Applied Sciences","","","","",""
"uuid:6dfd4bae-d966-4ddd-ace9-74ccf42504de","http://resolver.tudelft.nl/uuid:6dfd4bae-d966-4ddd-ace9-74ccf42504de","Mechanism of Persistent Luminescence in Eu2+ and Dy3+ Codoped Aluminate and Silicate Compounds","Dorenbos, P.","","2005","A mechanism of persistent luminescence that was proposed in 1996 for SrAl2O4:Eu2+;Dy3+ has been widely adopted to explain afterglow in many Eu2+ and Dy3+ codoped aluminates and silicates. The mechanism involves the thermally activated release of a hole from Eu2+ in its excited 5d state to the valence band which is subsequently trapped by Dy3+. In this work the location of the lanthanide energy levels relative to the valence and conduction band of various compounds is presented. It is shown that the mechanism of persistent luminescence cannot be correct. An alternative model that involves the ionization of the 5d electron to conduction band states and subsequent trapping by Dy3+ is proposed. The level schemes are consistent, both qualitatively and quantitatively, with many observations regarding persistent luminescence. They also provide insight into the mechanism of thermal quenching of Eu2+ 5d-4f emission.","europium; dysprosium; silicon compounds; calcium compounds; gallium compounds; strontium compounds; electroluminescence; phosphors; afterglows; excited states; valence bands; conduction bands; ionisation; quenching (thermal)","en","journal article","The Electrochemical Society","","","","","","","","Applied Sciences","RRR/Radiation, Radionuclides and Reactors","","","",""
"uuid:79dad7a2-0cd0-485a-9b20-86a39577faae","http://resolver.tudelft.nl/uuid:79dad7a2-0cd0-485a-9b20-86a39577faae","Scintillation Properties of LuI3:Ce^3+-High Light Yield Scintillators","Birowosuto, M.D.; Dorenbos, P.; van Eijk, C.W.E.; Kramer, K.W.; Gudel, H.U.","","2005","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:65500ea3-2970-45a5-852a-cebe5e0a28fe","http://resolver.tudelft.nl/uuid:65500ea3-2970-45a5-852a-cebe5e0a28fe","Ab initio calculation of the contribution from anion dipole polarization and dynamic correlation to 4f-5d excitations of Ce3+ in ionic compounds","Andriessen, J.; Dorenbos, P.; van Eijk, C.W.E.","","2005","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:2e175062-8f5a-4579-88c4-f1ad8031c8e6","http://resolver.tudelft.nl/uuid:2e175062-8f5a-4579-88c4-f1ad8031c8e6","Thermal quenching of Eu2+ 5d-4f luminescence in inorganic compounds","Dorenbos, P.","","2005","","","en","journal article","IOP","","","","","","","","Applied Sciences","","","","",""
"uuid:320553d3-3b50-44be-b3e5-126ff2c575db","http://resolver.tudelft.nl/uuid:320553d3-3b50-44be-b3e5-126ff2c575db","5d electron delocalization of Ce3+ and Pr3+ in Y2SiO5 and Lu2SiO5","van der Kolk, E.; Dorenbos, P.; van Eijk, C.W.E.; Basun, S.A.; Imbusch, G.F.; Yen, W.M.","","2005","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:2d421677-69f4-4aaf-8f79-c0b183146c9c","http://resolver.tudelft.nl/uuid:2d421677-69f4-4aaf-8f79-c0b183146c9c","Energy levels of lanthanide ions in a Lu2Si2O7 host","Pidol, L.; Viana, B.; Galtayries, A.; Dorenbos, P.","","2005","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:f50f6306-32b3-42de-a30b-107d2a47c900","http://resolver.tudelft.nl/uuid:f50f6306-32b3-42de-a30b-107d2a47c900","Thermally stimulated electron delocalization and luminescence quenching of Ce impurities in GdAlO3","van der Kolk, E.; Dorenbos, P.; de Haas, J.T.M.; van Eijk, C.W.E.","","2005","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:10d715ba-4fff-4999-983f-093cd87679df","http://resolver.tudelft.nl/uuid:10d715ba-4fff-4999-983f-093cd87679df","Gamma ray spectroscopy with a O19/spl times/19 mm/sup 3/ LaBr/sub 3/:0.5% Ce/sup 3+/ scintillator","Dorenbos, P.; de Haas, J.T.M.; van Eijk, C.W.E.","","2004","","","en","journal article","IEEE","","","","","","","","Applied Sciences","","","","",""
"uuid:ffb4e012-b619-46b5-a4da-7deeac693380","http://resolver.tudelft.nl/uuid:ffb4e012-b619-46b5-a4da-7deeac693380","New thermal neutron scintillators: Cs/sub 2/LiYCl/sub 6/:Ce/sup 3+/ and Cs/sub 2/LiYBr/sub 6/:Ce/sup 3+/","Bessiere, A.; Dorenbos, P.; van Eijk, C.W.E.; Kramer, K.W.; Gudel, H.U.","","2004","","","en","journal article","IEEE","","","","","","","","Applied Sciences","","","","",""
"uuid:413a1524-9d9f-40d6-929e-7a00ba3da2e8","http://resolver.tudelft.nl/uuid:413a1524-9d9f-40d6-929e-7a00ba3da2e8","Nonproportionality and energy resolution of a LaCl/sub 3/:10% Ce/sup 3+/ scintillation crystal","van Loef, E.V.D.; Mengesha, W.; Valentine, J.D.; Dorenbos, P.; van Eijk, C.W.E.","","2003","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:2fa0f552-95be-41b2-99f9-902b5a143fcd","http://resolver.tudelft.nl/uuid:2fa0f552-95be-41b2-99f9-902b5a143fcd","Anomalous 10-ns emission in Ce3+-doped Cs3LuCl6","Dorenbos, P.; Van Loef, E.V.D.; Van Eijk, C.W.E.; Krämer, K.W.; Güdel, H.U.","","2003","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:b91a6adc-dc31-4357-bb1f-05fb6beb83a8","http://resolver.tudelft.nl/uuid:b91a6adc-dc31-4357-bb1f-05fb6beb83a8","Influence of the anion on the spectroscopy and scintillation mechanism in pure and Ce3+-doped K2LaX5 and LaX3 (X=Cl, Br, I)","van Loef, E.V.D.; Dorenbos, P.; van Eijk, C.W.E.; Krämer, K.W.; Güdel, H.U.","","2003","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:cb9dacf5-4164-4abd-bc93-659a4230bf7f","http://resolver.tudelft.nl/uuid:cb9dacf5-4164-4abd-bc93-659a4230bf7f","Relating the energy of the [Xe]5d1 configuration of Ce3+ in inorganic compounds with anion polarizability and cation electronegativity","Dorenbos, P.","","2002","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:9f4ebd63-4073-449f-a0f0-8ca845da3ef5","http://resolver.tudelft.nl/uuid:9f4ebd63-4073-449f-a0f0-8ca845da3ef5","Thermal population of the 4f15d1 state in BaSO4:Pr3+","Vink, A.P.; Dorenbos, P.; van Eijk, C.W.E.","","2002","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:25d85bdf-4ad9-491b-a3bd-d73495f77370","http://resolver.tudelft.nl/uuid:25d85bdf-4ad9-491b-a3bd-d73495f77370","Scintillation properties of LaCl3:Ce3+ crystals: Fast, efficient, and high-energy resolution scintillators","van Loef, E.V.D.; Dorenbos, L.P.; van Eijk, C.W.E.; Kramer, K.; Gudel, H.U.","","2001","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:8245e0f6-63df-4d76-91d8-2edc38b03448","http://resolver.tudelft.nl/uuid:8245e0f6-63df-4d76-91d8-2edc38b03448","5d-level energies of Ce3+ and the crystalline environment. III. Oxides containing ionic complexes","Dorenbos, P.","","2001","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:127e60ca-e746-48c1-92cd-4bfabf7ecdd4","http://resolver.tudelft.nl/uuid:127e60ca-e746-48c1-92cd-4bfabf7ecdd4","Vacuum ultraviolet excitation and emission properties of Pr3+ and Ce3+ in MSO4 (M=Ba, Sr, and Ca) and predicting quantum splitting by Pr3+ in oxides and fluorides","van der Kolk, E.; Dorenbos, P.; Vink, A.P.; Perego, R.C.; van Eijk, C.E.W.; Lakshmanan, A.R.","","2001","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:7df2692d-a9c0-442c-ae09-2f0c5e0e54eb","http://resolver.tudelft.nl/uuid:7df2692d-a9c0-442c-ae09-2f0c5e0e54eb","5d-level energies of Ce3+ Chloride, bromide, and II. and the crystalline environment. iodide compounds","Dorenbos, P.","","2000","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:d79c6139-b11a-443d-bc01-505f3d2303e4","http://resolver.tudelft.nl/uuid:d79c6139-b11a-443d-bc01-505f3d2303e4","5d-level energies of Ce3+ Fluoride I. and the crystalline environment. compounds","Dorenbos, P.","","2000","","","en","journal article","American Physical Society","","","","","","","","","","","","",""
"uuid:7287dd4d-21b6-49b7-ba5c-77eb5a2e3ac9","http://resolver.tudelft.nl/uuid:7287dd4d-21b6-49b7-ba5c-77eb5a2e3ac9","Scintillation properties of RbGd2Br7:Ce. Advantages and limitations","Guillot-Noel, O.; van't Spijker, J.C.; de Haas, J.T.M.; Dorenbos, P.; van Eijk, C.W.E.; Kramer, K.W.; Gudel, H.U.","","1999","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:cd30e603-4854-4065-bba6-3c3468ad4abd","http://resolver.tudelft.nl/uuid:cd30e603-4854-4065-bba6-3c3468ad4abd","Proceedings of the international conference on inorganic scintillators and their applications, Delft, The Netherlands, 28 August - September 1, 1995: SCINT 95","Dorenbos, P.; Van Eijk, C.W.E.","","1996","","inorganic scintillators; radiation detection; scintillation crystals; luminescence","en","book","Delft University Press","","","","","","","","Delft University of Technology","","","","",""
"uuid:ca71b8c4-9e9e-4a3e-83d5-96eac4e144c5","http://resolver.tudelft.nl/uuid:ca71b8c4-9e9e-4a3e-83d5-96eac4e144c5","Non-proportionality in the scintillation response and the energy resolution obtainable with scintillation crystals","Dorenbos, P.; de Haas, J.T.M.; van Eijk, C.W.E.","","1995","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:74716232-591c-4928-a83e-6737e8288fd0","http://resolver.tudelft.nl/uuid:74716232-591c-4928-a83e-6737e8288fd0","Nd3+ and Pr3+ doped inorganic scintillators","van Eijk, C.W.E.; Dorenbos, P.; Visser, R.","","1994","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:0ac89b5e-8d90-4e9d-9ae3-ac226db65e34","http://resolver.tudelft.nl/uuid:0ac89b5e-8d90-4e9d-9ae3-ac226db65e34","Nonlinear response in the scintillation yield of Lu2SiO 5:Ce3+","Dorenbos, P.; de Haas, J.T.M.; van Eijk, C.W.E.; Melcher, C.L.; Schweitzer, J.S.","","1994","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:4736741b-fd5d-449f-a941-9e1d9e9117fd","http://resolver.tudelft.nl/uuid:4736741b-fd5d-449f-a941-9e1d9e9117fd","Scintillation properties of some Ce3+ and Pr3+ doped inorganic crystals","Dorenbos, P.; Visser, R.; van Eijk, C.W.E.; Khaidukov, N.M.; Korzhik, M.V.","","1993","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:c40e5c16-7bf2-4641-84d9-1764a0d3f01c","http://resolver.tudelft.nl/uuid:c40e5c16-7bf2-4641-84d9-1764a0d3f01c","Absolute light yield measurements on BaF2 crystals and the quantum efficiency of several photomultiplier tubes","Dorenbos, P.; de Haas, J.T.M.; Visser, R.; van Eijk, C.W.E.; Hollander, R.W.","","1993","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:ab1d9c43-63b1-4600-9305-3dc5644acc2a","http://resolver.tudelft.nl/uuid:ab1d9c43-63b1-4600-9305-3dc5644acc2a","Photon yields and decay times of cross luminescence in ionic crystals","Dorenbos, P.; Visser, R.; van Eijk, C.W.E.; Valbis, J.; Khaidukov, N.M.","","1992","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:9a0e7934-6275-433e-ae2e-3c2cb157bd15","http://resolver.tudelft.nl/uuid:9a0e7934-6275-433e-ae2e-3c2cb157bd15","Scintillation properties of Ce3+ doped BaF2 crystals","Visser, R.; Dorenbos, P.; van Eijk, C.W.E.; Hollander, R.W.; Schotanus, P.","","1991","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:8d4530bc-a975-41dc-8005-fc2ca793973d","http://resolver.tudelft.nl/uuid:8d4530bc-a975-41dc-8005-fc2ca793973d","Scintillation properties of Nd3+ doped LaF3 crystals","Dorenbos, P.; van Eijk, C.W.E.; Hollander, R.W.; Schotanus, P.","","1990","","","en","journal article","IEEE","","","","","","","","","","","","",""
"uuid:8469d331-9912-4f15-a24d-8fffe7e68bc8","http://resolver.tudelft.nl/uuid:8469d331-9912-4f15-a24d-8fffe7e68bc8","Development of silt measuring methods: Electronic signal processing, part II - a second generation acoustic measuring system","Gervink, B.J.G.M.; Dorenbos, G.J.; Berkhoudt, N.","","1989","","gegevensverwerking; data processing; zwevend-transportmeters; suspended load meters; akoestische meting; acoustic measurement; silttransport; silt transport; slibgehaltemeters; mud content meters","en","report","Deltares (WL)","","","","","","","","","","","","",""
"uuid:663454b4-365c-48c3-b8c3-edf2bb4a39da","http://resolver.tudelft.nl/uuid:663454b4-365c-48c3-b8c3-edf2bb4a39da","Development of silt measuring methods: Electronic signal processing, part I - a detection method for HF-bursts","Dorenbos, G.J.","","1987","","meetmethoden; measuring methods; silt; silt; meetinstrumenten; measuring instruments; detectie; detection; slibgehalte; mud content","en","report","Deltares (WL)","","","","","","","","","","","","",""