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Mulder, J.T. (author), Kirkwood, N.R.M. (author), De Trizio, Luca (author), Li, Chen (author), Bals, Sara (author), Manna, L. (author), Houtepen, A.J. (author)Indium phosphide quantum dots (QDs) have drawn attention as alternatives to cadmium- and lead-based QDs that are currently used as phosphors in lamps and displays. The main drawbacks of InP QDs are, in general, a lower photoluminescence quantum yield (PLQY), a decreased color purity, and poor chemical stability. In this research, we attempted...journal article 2020
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Crisp, R.W. (author), Hashemi, Fatemeh S.M. (author), Alkemade, J. (author), Kirkwood, N.R.M. (author), Grimaldi, G. (author), Kinge, S.S. (author), Siebbeles, L.D.A. (author), van Ommen, J.R. (author), Houtepen, A.J. (author)To improve the stability and carrier mobility of quantum dot (QD) optoelectronic devices, encapsulation or pore infilling processes are advantageous. Atomic layer deposition (ALD) is an ideal technique to infill and overcoat QD films, as it provides excellent control over film growth at the sub-nanometer scale and results in conformal...journal article 2020
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Lawrie, W.I.L. (author), Hendrickx, N.W. (author), van Riggelen, F. (author), Russ, M.F. (author), Petit, L. (author), Sammak, A. (author), Scappucci, G. (author), Veldhorst, M. (author)We investigate hole spin relaxation in the single- and multihole regime in a 2 × 2 germanium quantum dot array. We find spin relaxation times T1 as high as 32 and 1.2 ms for quantum dots with single- and five-hole occupations, respectively, setting benchmarks for spin relaxation times for hole quantum dots. Furthermore, we investigate qubit...journal article 2020
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Spoor, F.C.M. (author), Grimaldi, G. (author), Kinge, Sachin (author), Houtepen, A.J. (author), Siebbeles, L.D.A. (author)Carrier multiplication (CM) is the process in which multiple electron–hole pairs are created upon absorption of a single photon in a semiconductor. CM by an initially hot charge carrier occurs in competition with cooling by phonon emission, with the respective rates determining the CM efficiency. Up until now, CM rates have only been calculated...journal article 2019
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Tunable Coupling and Isolation of Single Electrons in Silicon Metal-Oxide-Semiconductor Quantum DotsEenink, H.G.J. (author), Petit, L. (author), Lawrie, W.I.L. (author), Clarke, J. S. (author), Vandersypen, L.M.K. (author), Veldhorst, M. (author)Extremely long coherence times, excellent single-qubit gate fidelities, and two-qubit logic have been demonstrated with silicon metal-oxide-semiconductor spin qubits, making it one of the leading platforms for quantum information processing. Despite this, a long-standing challenge in this system has been the demonstration of tunable tunnel...journal article 2019
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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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Crisp, R.W. (author), Kirkwood, N.R.M. (author), Grimaldi, G. (author), Kinge, Sachin (author), Siebbeles, L.D.A. (author), Houtepen, A.J. (author)InP and InZnP colloidal quantum dots (QDs) are promising materials for application in light-emitting devices, transistors, photovoltaics, and photocatalytic cells. In addition to possessing an appropriate bandgap, high absorption coefficient, and high bulk carrier mobilities, the intrinsic toxicity of InP and InZnP is much lower than for...journal article 2018
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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
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Island, J.O. (author)In this thesis we investigate superconducting hybrids made from two material systems, namely, molecules and layered materials. For studies of superconducting phenomena in molecular junctions we develop two platforms which rely on the superconducting proximity effect to preserve pre-existing nano-gap formation techniques and bonding chemistries....doctoral thesis 2016
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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
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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
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- Van den Berg, J.W.G. (author) doctoral thesis 2014
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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
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Braakman, F.R. (author)The coherent coupling of electron charges and spins is investigated in small quantum dot arrays.doctoral thesis 2013
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- Keijzers, C.J.H. (author) doctoral thesis 2012
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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
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Perinetti, U. (author)This thesis presents different optical experiments performed on semiconductor quantum dots. These structures allow to confine a small number of electrons and holes to a tiny region of space, some nm across. The aim of this work was to study the basic properties of different types of quantum dots made of various materials and with different...doctoral thesis 2011
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Liu, X.L. (author)Graphene is an exceptionally thin semiconductor that consists of only one atomic layer of carbon atoms. The electrons in graphene live in a strictly two-dimensional (2D) world. In addition to this remarkable 2Dness, it is also peculiar that the behavior of the electrons in graphene is governed by the Dirac equation rather than the well known...doctoral thesis 2010
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Götz, G.T.J. (author)We experimentally investigate Quantum Dots, formed in Carbon Nanotubes. The first part of this thesis deals with charge sensing on such quantum dots. The charge sensor is a metallic Single-electron-transistor, sensitive to the charge of a single electron on the quantum dot. We use this technique for real-time charge readout and precise tuning of...doctoral thesis 2010
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Akopian, N. (author), Van Weert, M. (author), Van Kouwen, M. (author), Algra, R. (author), Liu, L. (author), Patriarche, G. (author), Harmand, J.C. (author), Bakkers, E. (author), Kouwenhoven, L. (author), Zwiller, V. (author)In this paper we present our recent developments in control and manipulation of individual spins and photons in a single nanowire quantum dot. Specific examples include demonstration of optical excitation of single spin states, charge tunable quantum devices and single photon sources. We will also discuss our recent discovery of a new type of...conference paper 2010