- document
-
Limpens, R. (author), Luxembourg, S.L. (author), Weeber, A.W. (author), Gregorkiewicz, T. (author)One of the important obstacles on the way to application of Si nanocrystals for development of practical devices is their typically low emissivity. In this study we explore the limits of external quantum yield of photoluminescence of solid-state dispersions of Si nanocrystals in SiO2. By making use of a low-temperature hydrogen passivation...journal article 2016
- document
-
Van Den Berg, R. (author)Were stuck with a chicken-and-egg-problem: solar cells are expensive, so they dont get sold, which keeps the production volume low, so the price remains high.However, within a decade the price of electricity from a solar panel will be comparable to that of conventional mains power, says Dr. Albert Goossens, associate professor at the laboratory...journal article 2000
- document
-
Barthelemy, P.J.C. (author), Vandersypen, L.M.K. (author)Quantum mechanics often results in extremely complex phenomena, especially when the quantum system under consideration is composed of many interacting particles. The states of these many-body systems live in a space so large that classical numerical calculations cannot compute them. Quantum simulations can be used to overcome this problem:...journal article 2013
- document
-
Blaauboer, M. (author)Using master equations, we present an analytical solution of the time evolution of an entangled electron spin pair which can occupy 36 different quantum states in a double quantum dot nanostructure. This solution is exact, given a few realistic assumptions, and takes into account relaxation and decoherence rates of the electron spins as...journal article 2005
- document
-
Forn-Díaz, P. (author), Schouten, R.N. (author), Den Braver, W.A. (author), Mooij, J.E. (author), Harmans, C.J.P.M. (author)We fabricated and tested a squelch circuit consisting of a copper powder filter with an embedded Josephson junction connected to ground. For small signals (squelch ON), the small junction inductance attenuates strongly from dc to at least 1 GHz, while for higher frequencies dissipation in the copper powder increases the attenuation exponentially...journal article 2009
- document
-
Reimer, M.E. (author), van Kouwen, M.P. (author), Barkelid, M. (author)We report recent progress toward on-chip single photon emission and detection in the near infrared utilizing semiconductor nanowires. Our single photon emitter is based on a single InAsP quantum dot embedded in a p-n junction defined along the growth axis of an InP nanowire. Under forward bias, light is emitted from the single quantum dot by...journal article 2011
- document
-
Vink, I.T. (author), Nooitgedagt, T. (author), Schouten, R.N. (author), Vandersypen, L.M.K. (author), Wegscheider, W. (author)The authors employ a cryogenic high electron mobility transistor (HEMT) amplifier to increase the bandwidth of a charge detection setup with a quantum point contact (QPC) charge sensor. The HEMT is operating at 1?K and the circuit has a bandwidth of 1?MHz. The noise contribution of the HEMT at high frequencies is only a few times higher than...journal article 2007
- document
-
Bodoky, F. (author), Belzig, W. (author), Bruder, C. (author)We investigate the current and noise characteristics of a double quantum dot system. The strong correlations induced by the Coulomb interaction and the Pauli principle create entangled two-electron states and lead to signatures in the transport properties. We show that the interaction parameter Ø, which measures the admixture of the double...journal article
- document
-
Lodari, M. (author), Hendrickx, N.W. (author), Lawrie, W.I.L. (author), Hsiao, T. (author), Vandersypen, L.M.K. (author), Sammak, A. (author), Veldhorst, M. (author), Scappucci, G. (author)We engineer planar Ge/SiGe heterostructures for low disorder and quiet hole quantum dot operation by positioning the strained Ge channel 55 nm below the semiconductor/dielectric interface. In heterostructure field effect transistors, we measure a percolation density for two-dimensional hole transport of 2.1 × 10 10 cm−2 , indicative of a very...journal article 2021
- document
-
Gudjónsdóttir, S. (author), Houtepen, A.J. (author)Arguably the most controllable way to control the charge density in various semiconductors, is by electrochemical doping. However, electrochemically injected charges usually disappear within minutes to hours, which is why this technique is not yet used to make semiconductor devices. In this manuscript, electrochemical doping of different...journal article 2020
- document
-
Vonk, Sander J.W. (author), Heemskerk, Bart A.J. (author), Keitel, Robert C. (author), Hinterding, Stijn O.M. (author), Geuchies, J.J. (author), Houtepen, A.J. (author), Rabouw, Freddy T. (author)Broadening of multiexciton emission from colloidal quantum dots (QDs) at room temperature is important for their use in high-power applications, but an in-depth characterization has not been possible until now. We present and apply a novel spectroscopic method to quantify the biexciton line width and biexciton binding energy of single CdSe...journal article 2021
- document
-
Xia, Fei (author), Gevers, Monique (author), Fognini, Andreas (author), Mok, Aaron T. (author), Li, Bo (author), Akbari, Najva (author), Esmaeil Zadeh, I.Z. (author), Qin-Dregely, Y. (author), Xu, Chris (author)Optical microscopy is a valuable tool for in vivo monitoring of biological structures and functions because of its noninvasiveness. However, imaging deep into biological tissues is challenging due to the scattering and absorption of light. Previous research has shown that the two optimal wavelength windows for high-resolution deep mouse brain...journal article 2021
- document
-
Vogel, Y.B. (author), Stam, M. (author), Mulder, J.T. (author), Houtepen, A.J. (author)We present a strategy to actively engineer long-range charge transport in colloidal quantum dot assemblies by using ligand functionalities that introduce electronic states and provide a path for carrier transfer. This is a shift away from the use of inactive spacers to modulate charge transport through the lowering of the tunneling barrier...journal article 2022
- document
-
Llusar, Jordi (author), du Fossé, I. (author), Hens, Zeger (author), Houtepen, A.J. (author), Infante, Ivan (author)Although density functional theory (DFT) calculations have been crucial in our understanding of colloidal quantum dots (QDs), simulations are commonly carried out on QD models that are significantly smaller than those generally found experimentally. While smaller models allow for efficient study of local surface configurations, increasing the...journal article 2023
- document
-
Mangnus, Mark J.J. (author), de Wit, Jur W. (author), Vonk, Sander J.W. (author), Geuchies, J.J. (author), Albrecht, Wiebke (author), Bals, Sara (author), Houtepen, A.J. (author), Rabouw, Freddy T. (author)In recent years, quantum dots (QDs) have emerged as bright, color-tunable light sources for various applications such as light-emitting devices, lasing, and bioimaging. One important next step to advance their applicability is to reduce particle-to-particle variations of the emission properties as well as fluctuations of a single QD’s...journal article 2023
- document
-
Ungerer, J. H. (author), Chevalier Kwon, P. (author), Patlatiuk, T. (author), Ridderbos, J. (author), Kononov, A. (author), Sarmah, D. (author), Bakkers, E.P.A.M. (author), Zumbühl, D. (author), Schönenberger, C. (author)Spin qubits in germanium are a promising contender for scalable quantum computers. Reading out of the spin and charge configuration of quantum dots formed in Ge/Si core/shell nanowires is typically performed by measuring the current through the nanowire. Here, we demonstrate a more versatile approach on investigating the charge configuration...journal article 2023
- document
-
Almeida, Guilherme (author), van der Poll, L.M. (author), Evers, W.H. (author), Szoboszlai, Emma (author), Vonk, Sander J.W. (author), Rabouw, Freddy T. (author), Houtepen, A.J. (author)Indium phosphide colloidal quantum dots (CQDs) are the main alternative for toxic and restricted Cd based CQDs for lighting and display applications. Here we systematically report on the size-dependent optical absorption, ensemble, and single particle photoluminescence (PL) and biexciton lifetimes of core-only InP CQDs. This systematic study...journal article 2023
- document
-
Pietra, F. (author), De Trizio, L. (author), Hoekstra, Anne W. (author), Renaud, N. (author), Prato, Mirko (author), Grozema, F.C. (author), Baesjou, Patrick J. (author), Koole, Rolf (author), Manna, L. (author), Houtepen, A.J. (author)Colloidal quantum dots (QDs) show great promise as LED phosphors due to their tunable narrow-band emission and ability to produce high-quality white light. Currently, the most suitable QDs for lighting applications are based on cadmium, which presents a toxicity problem for consumer applications. The most promising cadmium-free candidate QDs...journal article 2016
- document
-
Stam, M. (author), du Fossé, I. (author), Infante, Ivan (author), Houtepen, A.J. (author)Quantum dots (QDs) are known for their size-dependent optical properties, narrow emission bands, and high photoluminescence quantum yield (PLQY), which make them interesting candidates for optoelectronic applications. In particular, InP QDs are receiving a lot of attention since they are less toxic than other QD materials and are hence...journal article 2023
- document
-
Marino, Emanuele (author), Kodger, Thomas E. (author), Crisp, R.W. (author), Timmerman, Dolf (author), MacArthur, Katherine E. (author), Heggen, Marc (author), Schall, Peter (author)Solar devices based on semiconductor nanoparticles require the use of conductive ligands; however, replacing the native, insulating ligands with conductive metal chalcogenide complexes introduces structural defects within the crystalline nanostructure that act as traps for charge carriers. We utilized atomically thin semiconductor...journal article 2017