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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 53 for “"Carrier Recombination"”.
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Development of non-contact measurements for carrier recombination lifetime
Includes bibliographical references (pages 108-112).
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Charge carrier recombination and open circuit voltage in organic solar cells
… Besides open circuit voltage losses the recombination of charges in organic solar cells is also a prevailing research topic, especially with respect to the influence of trap states. The exploratory focus of this work is therefore set, on the one hand, on the development of hybrid …
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Defect energies, band alignments, and charge carrier recombination in polycrystalline Cu(In,Ga)(Se,S)2 alloys
… the defect energies, band alignments, and charge carrier recombination in polycrystalline Cu(In1-xGax)(Se1-ySy)2 chalcopyrite thin films and the interrelationship with the alloy composition. Photoluminescence spectroscopy of investigated Cu-poor Cu(In,Ga)(Se,S)2 layers generally shows broad …
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Analysis of transistor laser intra-cavity photon-assisted tunneling for direct voltage modulation
… by its current modulation scheme in which the carrier recombination lifetime in the active region governs the ultimate speed of operation. The transistor laser, due to its enhanced carrier recombination in the bipolar junction transistor base region, is a promising candidate to replace the …
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Design, fabrication, and characterization of high-speed light-emitting transistors and microcavity lasers
Carrier spontaneous recombination lifetime has been thought to be limited to ~ 1 ns in light-emitting diodes and diode lasers for the past forty years. In the present work the recombination lifetime demonstrated is able to be “tailored” (reduced) by the provided material system, cavity size, and …
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Surface and bulk passivation of multicrystalline silicon solar cells by silicon nitride (H) layer : modeling and experiments
… of interface state density, D1. The surface recombination velocity can be described by Shockley-Read-Hall (SRH) statistics. Current SRH formalisms have failed to explain the surface recombination mechanism in terms of injection level dependence as has been observed by lifetime measurements. …
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Three Grains, Two Photons and a Colourful Diamond
… suppress it. We then unveil buried charge-carrier recombination pathways in both thin film and micro-crystal methylammonium lead halide perovskite structures through 3D photoluminescence tomography acquired using two-photon confocal microscopy. These measurements reveal that light-induced …
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Effects of Intrinsic and Extrinsic Point Defects on Epitaxial Single Crystal Copper-Indium(1-X)-Gallium(x)-Diselenide
… or severe radiation damage affects minority carrier recombination kinetics. In all cases the photoconductivity was found to be unaffected other than by changes in mobility. (Abstract shortened by UMI.).
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Study of carrier and gain dynamics in InGaAsN quantum well lasers
… This is done through the investigation of the carrier recombination dynamics, nonlinear gain dynamics and carrier capture and escape processes in InGaAsN quantum well lasers. The carrier dynamics is investigated through a comprehensive temperature dependent steady state photoluminescence (PL) …
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Nanoscale optoelectronic properties in traditional and emerging materials for light-emitting diodes
… as well-width fluctuations or V-pit defects on carrier recombination. Organic-inorganic perovskites have begun to attract attention as a potential next-generation LED material, but these nascent materials suffer from rapid material degradation under device operating conditions. Understanding …
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Compact modeling of neutron damage effects in a bipolar junction transistor
… lattice defects, which can dramatically increase carrier recombination rate. In turn, the increase in recombination rate degrades the current gain. Two approaches were taken in the development of a compact BJT model that include the effects of static neutron damage. One approach is based on the …
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Semiconductor Optical Preamplifiers for Use in High-Speed Integrated Photoreceivers at 1.3 Um and 1.55 Um
… well as low-frequency effects attributed to the carrier-recombination lifetime. Second, a self-aligned processing scheme is developed for fabricating semiconductor lasers, optical amplifiers, and photodetectors in this material system; this scheme emphasizes fabrication simplicity and low contact …
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Characterization of VCSELs for Circuit Simulation
… The first model includes the nonlinear gain and carrier recombination characteristics. Rate equation parameters are extracted from static current-light-voltage (I-L-V), time domain turn-on delay, and ac reflection and transmission measurements. The parameters are demonstrated to be suitable for …
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Direct tunneling modulation and signal mixing of semiconductor lasers
… modulation speed limit by further reducing the carrier recombination lifetime. In addition, a recently discovered tunneling mechanism inside the transistor laser device structure paves the way for ultrahigh-speed direct modulation of laser optical output. In this work, the operation of the …
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Carrier transport, recombination, and the effects of grain boundaries in polycrystalline cadmium telluride thin films for photovoltaics
… in covalently-bonded semiconductors (a) act as carrier recombination centers, and (b) lead to localized energy states, causing carrier trapping. Despite significant research to date, the mechanism responsible for the superior current collection properties of polycrystalline CdTe solar cells has …
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Investigation of carrier dynamics in InN, InGaN, and GaAsBi by optical pump-probe techniques /
The thesis is dedicated to investigation of carrier dynamics in InN, InGaN, and GaAsBi heterostructures by using light-induced transient gratings and differential transmission techniques. The experimental studies in a wide range of excess carrier densities and temperatures revealed that …
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Lattice Engineering of III-Nitride Heterostructures and Their Applications
… and the composition modulation has impacts on carrier recombination dynamics. We also showed that the controlled relaxation of a very thin AlN buffer (20 ~ 30 nm) or a graded composition InGaN buffer can significantly reduce the defect density of a subsequent epitaxial layer. Finally, we …
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Surface-mediated mechanisms for defect engineering in zinc oxide
… (VO) are typically numerous and serve as carrier recombination centers or electron current scatterers. One solution suggested by our laboratory is to thermally inject highly mobile charged oxygen interstitials (Oi) through metal oxide surfaces from the gas phase to annihilate VO in the …
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Izovalentiškai legiruotų cinko selenido scintiliacinių kristalų priemaišinės liuminescencijos tyrimai /
… revealed peculiarities of the radiative recombination mechanisms in ZnSe doped with tellurium and oxygen. A new carrier recombination model in ZnSe crystals doped with tellurium and oxygen is proposed and numerical simulation of the PL intensity dependence on temperature is performed. The …
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Izovalentiškai legiruotų cinko selenido scintiliacinių kristalų priemaišinės liuminescencijos tyrimai /
… revealed peculiarities of the radiative recombination mechanisms in ZnSe doped with tellurium and oxygen. A new carrier recombination model in ZnSe crystals doped with tellurium and oxygen is proposed and numerical simulation of the PL intensity dependence on temperature is performed. The …
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