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Cryo-EM structure of gas vesicles for buoyancy-controlled motility

Huber, S. (author), Terwiel, D. (author), Evers, W.H. (author), Maresca, D. (author), Jakobi, A. (author)

Gas vesicles are gas-filled nanocompartments that allow a diverse group of bacteria and archaea to control their buoyancy. The molecular basis of their properties and assembly remains unclear. Here, we report the 3.2 Å cryo-EM structure of the gas vesicle shell made from the structural protein GvpA that self-assembles into hollow helical...

journal article 2023

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Nucleation and Growth of Bipyramidal Yb:LiYF4 Nanocrystals─Growing Up in a Hot Environment

Mulder, J.T. (author), Jenkinson, Kellie (author), Toso, Stefano (author), Prato, Mirko (author), Evers, W.H. (author), Bals, Sara (author), Manna, Liberato (author), Houtepen, A.J. (author)

Lanthanide-doped LiYF4 (Ln:YLF) is commonly used for a broad variety of optical applications, such as lasing, photon upconversion and optical refrigeration. When synthesized as nanocrystals (NCs), this material is also of interest for biological applications and fundamental physical studies. Until now, it was unclear how Ln:YLF NCs grow from...

journal article 2023

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Tuning the Driving Force for Charge Transfer in Perovskite-Chromophore Systems

Wei, Z. (author), Mulder, J.T. (author), Dubey, R. (author), Evers, W.H. (author), Jager, W.F. (author), Houtepen, A.J. (author), Grozema, F.C. (author)

Understanding the interplay between the kinetics and energetics of photophysical processes in perovskite-chromophore hybrid systems is crucial for realizing their potential in optoelectronics, photocatalysis, and light-harvesting applications. By combining steady-state optical characterizations and transient absorption spectroscopy, we have...

journal article 2023

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Size-Dependent Optical Properties of InP Colloidal Quantum Dots

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

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Zero-Threshold Optical Gain in Electrochemically Doped Nanoplatelets and the Physics behind It

Geuchies, J.J. (author), Dijkhuizen, Robbert (author), Koel, Marijn (author), Grimaldi, G. (author), du Fossé, I. (author), Evers, W.H. (author), Hens, Zeger (author), Houtepen, A.J. (author)

Colloidal nanoplatelets (NPLs) are promising materials for lasing applications. The properties are usually discussed in the framework of 2D materials, where strong excitonic effects dominate the optical properties near the band edge. At the same time, NPLs have finite lateral dimensions such that NPLs are not true extended 2D structures. Here...

journal article 2022

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Nanofluidic chips for cryo-EM structure determination from picoliter sample volumes

Huber, S. (author), Sarajlic, Edin (author), Huijink, Roeland (author), Weis, Felix (author), Evers, W.H. (author), Jakobi, A. (author)

Cryogenic electron microscopy has become an essential tool for structure determination of biological macromolecules. In practice, the difficulty to reliably prepare samples with uniform ice thickness still represents a barrier for routine high-resolution imaging and limits the current throughput of the technique. We show that a nanofluidic...

journal article 2022

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Multivalent interactions facilitate motor-dependent protein accumulation at growing microtubule plus-ends

Maan, R. (author), Reese, L. (author), Volkov, V. (author), King, M.R. (author), van der Sluis, E.O. (author), Andrea, N. (author), Evers, W.H. (author), Jakobi, A. (author), Dogterom, A.M. (author)

Growing microtubule ends organize end-tracking proteins into comets of mixed composition. Here using a reconstituted fission yeast system consisting of end-binding protein Mal3, kinesin Tea2 and cargo Tip1, we found that these proteins can be driven into liquid-phase droplets both in solution and at microtubule ends under crowding conditions....

journal article 2022

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The Fine-Structure Constant as a Ruler for the Band-Edge Light Absorption Strength of Bulk and Quantum-Confined Semiconductors

Prins, P. Tim (author), Alimoradi Jazi, M. (author), Killilea, Niall A. (author), Evers, W.H. (author), Geiregat, Pieter (author), Heiss, Wolfgang (author), Houtepen, A.J. (author), Delerue, Christophe (author), Hens, Zeger (author), Vanmaekelbergh, Daniel (author)

Low-dimensional semiconductors have found numerous applications in optoelectronics. However, a quantitative comparison of the absorption strength of low-dimensional versus bulk semiconductors has remained elusive. Here, we report generality in the band-edge light absorptance of semiconductors, independent of their dimensions. First, we...

journal article 2021

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The Polygonal Cell Shape and Surface Protein Layer of Anaerobic Methane-Oxidizing Methylomirabilis lanthanidiphila Bacteria

Gambelli, Lavinia (author), Mesman, Rob (author), Versantvoort, Wouter (author), Diebolder, Christoph A. (author), Engel, A.H. (author), Evers, W.H. (author), Jetten, Mike S.M. (author), Pabst, Martin (author), Daum, Bertram (author)

Methylomirabilis bacteria perform anaerobic methane oxidation coupled to nitrite reduction via an intra-aerobic pathway, producing carbon dioxide and dinitrogen gas. These diderm bacteria possess an unusual polygonal cell shape with sharp ridges that run along the cell body. Previously, a putative surface protein layer (S-layer) was observed...

journal article 2021

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Photogeneration Quantum Yield and Character of Free Charges and Excitons in PbSe Nanorods

Kulkarni, A. (author), Evers, W.H. (author), Van Waas, Thomas P. (author), Siebbeles, L.D.A. (author)

Lead selenide (PbSe) nanorods are of interest for applications in infrared LEDs, lasers, and photovoltaics due to the possibility of tuning their band gap from the far- to the near-infrared by decreasing their radius. We study the photogeneration quantum yield and properties of free charges and excitons in PbSe nanorods using a combination of...

journal article 2020

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Quantitative Electrochemical Control over Optical Gain in Quantum-Dot Solids

Geuchies, J.J. (author), Brynjarsson, Baldur (author), Grimaldi, G. (author), Gudjónsdóttir, S. (author), van der Stam, W. (author), Evers, W.H. (author), Houtepen, A.J. (author)

Solution-processed quantum dot (QD) lasers are one of the holy grails of nanoscience. They are not yet commercialized because the lasing threshold is too high: one needs >1 exciton per QD, which is difficult to achieve because of fast nonradiative Auger recombination. The threshold can, however, be reduced by electronic doping of the QDs,...

journal article 2020

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On the Stability of Permanent Electrochemical Doping of Quantum Dot, Fullerene, and Conductive Polymer Films in Frozen Electrolytes for Use in Semiconductor Devices

Gudjónsdóttir, S. (author), van der Stam, W. (author), Koopman, Christel (author), Kwakkenbos, Bob (author), Evers, W.H. (author), Houtepen, A.J. (author)

Semiconductor films that allow facile ion transport can be electronically doped via electrochemistry, where the amount of injected charge can be controlled by the potential applied. To apply electrochemical doping to the design of semiconductor devices, the injected charge has to be stabilized to avoid unintentional relaxation back to the...

journal article 2019

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Hot-electron transfer in quantum-dot heterojunction films

Grimaldi, G. (author), Crisp, R.W. (author), Ten Brinck, Stephanie (author), Zapata, Felipe (author), van Ouwendorp, M. (author), Renaud, N. (author), Kirkwood, N.R.M. (author), Evers, W.H. (author), Kinge, S.S. (author), Infante, Ivan (author), Siebbeles, L.D.A. (author), Houtepen, A.J. (author)

Thermalization losses limit the photon-to-power conversion of solar cells at the high-energy side of the solar spectrum, as electrons quickly lose their energy relaxing to the band edge. Hot-electron transfer could reduce these losses. Here, we demonstrate fast and efficient hot-electron transfer between lead selenide and cadmium selenide...

journal article 2018

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Selective antimony reduction initiating the nucleation and growth of InSb quantum dots

Crisp, R.W. (author), Grimaldi, G. (author), De Trizio, Luca (author), Evers, W.H. (author), Kirkwood, N.R.M. (author), Kinge, Sachin (author), Manna, L. (author), Siebbeles, L.D.A. (author), Houtepen, A.J. (author)

Indium antimonide (InSb) quantum dots (QDs) have unique and interesting photophysical properties, but widespread experimentation with InSb QDs is lacking due to the difficulty in synthesizing this material. The key experimental challenge in fabricating InSb QDs is preparing a suitable Sb-precursor in the correct oxidation state that reacts...

journal article 2018

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Asymmetric Optical Transitions Determine the Onset of Carrier Multiplication in Lead Chalcogenide Quantum Confined and Bulk Crystals

Spoor, F.C.M. (author), Grimaldi, G. (author), Delerue, Christophe (author), Evers, W.H. (author), Crisp, R.W. (author), Geiregat, P.A. (author), Hens, Zeger (author), Houtepen, A.J. (author), Siebbeles, L.D.A. (author)

Carrier multiplication is a process in which one absorbed photon excites two or more electrons. This is of great promise to increase the efficiency of photovoltaic devices. Until now, the factors that determine the onset energy of carrier multiplication have not been convincingly explained. We show experimentally that the onset of carrier...

journal article 2018

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Efficient Steplike Carrier Multiplication in Percolative Networks of Epitaxially Connected PbSe Nanocrystals

Kulkarni, A. (author), Evers, W.H. (author), Tomić, Stanko (author), Beard, Matthew C. (author), Vanmaekelbergh, Daniel (author), Siebbeles, L.D.A. (author)

Carrier multiplication (CM) is a process in which a single photon excites two or more electrons. CM is of interest to enhance the efficiency of a solar cell. Until now, CM in thin films and solar cells of semiconductor nanocrystals (NCs) has been found at photon energies well above the minimum required energy of twice the band gap. The high...

journal article 2018

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The Role of Dopant Ions on Charge Injection and Transport in Electrochemically Doped Quantum Dot Films

Gudjónsdóttir, S. (author), van der Stam, W. (author), Kirkwood, Nicholas (author), Evers, W.H. (author), Houtepen, A.J. (author)

Control over the charge density is very important for implementation of colloidal semiconductor nanocrystals into various optoelectronic applications. A promising approach to dope nanocrystal assemblies is charge injection by electrochemistry, in which the charge compensating electrolyte ions can be regarded as external dopant ions. To gain...

journal article 2018

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Charge Mobility and Dynamics in Spin-Crossover Nanoparticles Studied by Time-Resolved Microwave Conductivity

Dugay, J. (author), Evers, W.H. (author), Torres-Cavanillas, Ramón (author), Giménez-Marqués, Mónica (author), Coronado, Eugenio (author), van der Zant, H.S.J. (author)

We use the electrodeless time-resolved microwave conductivity (TRMC) technique to characterize spin-crossover (SCO) nanoparticles. We show that TRMC is a simple and accurate means for simultaneously assessing the magnetic state of SCO compounds and charge transport information on the nanometer length scale. In the low-spin state from liquid...

journal article 2018

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Tuning and Probing the Distribution of Cu⁺ and Cu²⁺ Trap States Responsible for Broad-Band Photoluminescence in CuInS₂ Nanocrystals

van der Stam, W. (author), de Graaf, M. (author), Gudjónsdóttir, S. (author), Geuchies, J.J. (author), Dijkema, J.J. (author), Kirkwood, N.R.M. (author), Evers, W.H. (author), Longo, Alessandro (author), Houtepen, A.J. (author)

The processes that govern radiative recombination in ternary CuInS₂ (CIS) nanocrystals (NCs) have been heavily debated, but recently, several research groups have come to the same conclusion that a photoexcited electron recombines with a localized hole on a Cu-related trap state. Furthermore, it has been observed that single CIS...

journal article 2018

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Switching between Plasmonic and Fluorescent Copper Sulfide Nanocrystals

van der Stam, W. (author), Gudjónsdóttir, S. (author), Evers, W.H. (author), Houtepen, A.J. (author)

Control over the doping density in copper sulfide nanocrystals is of great importance and determines its use in optoelectronic applications such as NIR optical switches and photovoltaic devices. Here, we demonstrate that we can reversibly control the hole carrier density (varying from >10²² cm^-3 to intrinsic) in...

journal article 2017