The Experts below are selected from a list of 4722 Experts worldwide ranked by ideXlab platform
Qin Han - One of the best experts on this subject based on the ideXlab platform.
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the role of sb in the molecular beam epitaxy growth of 1 30 1 55 μm wavelength gainnas gaas quantum well with high Indium Content
Journal of Crystal Growth, 2006Co-Authors: Zhichuan C. Niu, Shiyong Zhang, Zheng Sun, Qin HanAbstract:Sb-assisted GaInNAs/GaAs quantum wells (QWs) with high (42.5%) Indium Content were investigated systematically. Transmission electron microscopy, reflection high-energy electron diffraction and photoluminescence (PL) measurements reveal that Sb acts as a surfactant to suppress three-dimensional growth. The improvement in the 1.55 mu m range is much more apparent than that in the 1.3 mu m range.. which can be attributed to the difference in N composition. The PL intensity and the full-width at half maximum of the 1.55 mu m single-QW were comparable with that of the 1.3 Am QWs. (c) 2006 Elsevier B.V. All rights reserved.
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1.3 µm high Indium Content (42.5%) GaInNAs/GaAs quantum wells grown by molecular beam epitaxy
physica status solidi (c), 2006Co-Authors: Zhichuan Niu, Shiyong Zhang, Zheng Sun, Qin HanAbstract:High structural and optical quality 1.3 mu m GaInNAs/GaAs quantum well (QW) samples with 42.5% Indium Content were successfully grown by molecular beam epitaxy. The growth of well layers was monitored by reflection high-energy electron diffraction (RHEED). Room temperature photoluminescence (PL) peak intensity of the GaIn0.425NAs/GaAs (6 nm / 20 nm) 3QW is higher than, and the full width at half maximum (FWHM) is comparable to, that of In0.425GaAs/GaAs 3QW, indicating improved optical quality due to strain compensation effects by introducing N to the high Indium Content InGaAs epilayer. The measured (004) X-ray rocking curve shows clear satellite peaks and Pendellosung fringes, suggesting high film uniformity and smooth interfaces. The cross sectional TEM measurements further reveal that there are no structural defects in such high Indium Content QWs. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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The role of Sb in the molecular beam epitaxy growth of 1.30–1.55 μm wavelength GaInNAs/GaAs quantum well with high Indium Content
Journal of Crystal Growth, 2006Co-Authors: Zhichuan C. Niu, Shiyong Zhang, Zheng Sun, Qin HanAbstract:Sb-assisted GaInNAs/GaAs quantum wells (QWs) with high (42.5%) Indium Content were investigated systematically. Transmission electron microscopy, reflection high-energy electron diffraction and photoluminescence (PL) measurements reveal that Sb acts as a surfactant to suppress three-dimensional growth. The improvement in the 1.55 mu m range is much more apparent than that in the 1.3 mu m range.. which can be attributed to the difference in N composition. The PL intensity and the full-width at half maximum of the 1.55 mu m single-QW were comparable with that of the 1.3 Am QWs. (c) 2006 Elsevier B.V. All rights reserved.
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High structural and optical quality 1.3 {mu}m GaInNAs/GaAs quantum wells with higher Indium Content grown by molecular-beam expitaxy
Applied Physics Letters, 2005Co-Authors: Shiyong Zhang, Zhichuan Niu, Zheng Sun, Qin HanAbstract:High structural and optical quality 1.3 mu m GaInNAs/GaAs quantum well (QW) samples with higher (42.5%) Indium Content were successfully grown by molecular-beam epitaxy. The cross-sectional transmission electron microscopy measurements reveal that there are no structural defects in such high Indium Content QWs. The room-temperature photoluminescence peak intensity of the GaIn0.425NAs/GaAs (6 nm/20 nm) 3QW is higher than, and the full width at half maximum is comparable to, that of In0.425GaAs/GaAs 3QW, indicating improved optical quality caused by strain compensation effect of introducing N to the high Indium Content InGaAs epilayer. (C) 2005 American Institute of Physics.
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high structural and optical quality 1 3 mu m gainnas gaas quantum wells with higher Indium Content grown by molecular beam expitaxy
Applied Physics Letters, 2005Co-Authors: Shiyong Zhang, Zhichuan Niu, Zheng Sun, Qin HanAbstract:High structural and optical quality 1.3 mu m GaInNAs/GaAs quantum well (QW) samples with higher (42.5%) Indium Content were successfully grown by molecular-beam epitaxy. The cross-sectional transmission electron microscopy measurements reveal that there are no structural defects in such high Indium Content QWs. The room-temperature photoluminescence peak intensity of the GaIn0.425NAs/GaAs (6 nm/20 nm) 3QW is higher than, and the full width at half maximum is comparable to, that of In0.425GaAs/GaAs 3QW, indicating improved optical quality caused by strain compensation effect of introducing N to the high Indium Content InGaAs epilayer. (C) 2005 American Institute of Physics.
Yong-hoon Cho - One of the best experts on this subject based on the ideXlab platform.
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Strong carrier localization and diminished quantum-confined Stark effect in ultra-thin high-Indium-Content InGaN quantum wells with violet light emission
Applied Physics Letters, 2013Co-Authors: Ho-sang Kwack, Chunghyun Park, Yang-seok Yoo, Soon-yong Kwon, Heejin Kim, Euijoon Yoon, Daniel Le-si Dang, Yong-hoon ChoAbstract:Here, we report on the optical and structural characteristics of violet-light-emitting, ultra-thin, high-Indium-Content (UTHI) InGaN/GaN multiple quantum wells (MQWs), and of conventional low-In-Content MQWs, which both emit at similar emission energies though having different well thicknesses and In compositions. The spatial inhomogeneity of In Content, and the potential fluctuation in high-efficiency UTHI MQWs were compared to those in the conventional low-In-Content MQWs. We conclude that the UTHI InGaN MQWs are a promising structure for achieving better quantum efficiency in the visible and near-ultraviolet spectral range, owing to their strong carrier localization and reduced quantum-confined Stark effect.
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Strong Carrier Localization and Diminished Quantum-confined Stark Effect in Ultra-thin High-Indium-Content InGaN Quantum Wells with Violet Light Emission
Applied Physics Letters, 2013Co-Authors: Ho-sang Kwack, Chunghyun Park, Yang-seok Yoo, Soon-yong Kwon, Heejin Kim, Euijoon Yoon, Le Si Dang, Yong-hoon ChoAbstract:International audienceHere, we report on the optical and structural characteristics of violet-light-emitting, ultra-thin, high-Indium-Content (UTHI) InGaN/GaN multiple quantum wells (MQWs), and of conventional low-In-Content MQWs, which both emit at similar emission energies though having different well thicknesses and In compositions. The spatial inhomogeneity of In Content, and the potential fluctuation in high-efficiency UTHI MQWs were compared to those in the conventional low-In-Content MQWs. We conclude that the UTHI InGaN MQWs are a promising structure for achieving better quantum efficiency in the visible and near-ultraviolet spectral range, owing to their strong carrier localization and reduced quantum-confined Stark effect
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Phase separations in graded-Indium Content InGaN/GaN multiple quantum wells and its function to high quantum efficiency
Journal of Semiconductors, 2012Co-Authors: Guo Hongying, Sun Yuan-ping, Yong-hoon Cho, Eun-kyung Suh, Hai-joon Lee, Rak-jun Choi, Yoon-bong HahnAbstract:Phase separations have been studied for graded-Indium Content InxGa1x N/GaN multiple quantum wells (MQWs) with different Indium Contents by means of photoluminescence (PL), cathodeluminescence (CL) and time-resolved PL (TRPL) techniques. Besides the main emission peaks, all samples show another 2 peaks at the high and low energy parts of the main peaks in PL when excited at 10 K. CL images show a clear contrast for 3 samples, which indicates an increasing phase separation with increasing Indium Content. TRPL spectra at 15 K of the main emissions show an increasing delay of rising time with Indium Content, which means a carrier transferring from low Indium Content structures to high Indium Content structures.
Zhichuan Niu - One of the best experts on this subject based on the ideXlab platform.
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1.3 µm high Indium Content (42.5%) GaInNAs/GaAs quantum wells grown by molecular beam epitaxy
physica status solidi (c), 2006Co-Authors: Zhichuan Niu, Shiyong Zhang, Zheng Sun, Qin HanAbstract:High structural and optical quality 1.3 mu m GaInNAs/GaAs quantum well (QW) samples with 42.5% Indium Content were successfully grown by molecular beam epitaxy. The growth of well layers was monitored by reflection high-energy electron diffraction (RHEED). Room temperature photoluminescence (PL) peak intensity of the GaIn0.425NAs/GaAs (6 nm / 20 nm) 3QW is higher than, and the full width at half maximum (FWHM) is comparable to, that of In0.425GaAs/GaAs 3QW, indicating improved optical quality due to strain compensation effects by introducing N to the high Indium Content InGaAs epilayer. The measured (004) X-ray rocking curve shows clear satellite peaks and Pendellosung fringes, suggesting high film uniformity and smooth interfaces. The cross sectional TEM measurements further reveal that there are no structural defects in such high Indium Content QWs. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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High structural and optical quality 1.3 {mu}m GaInNAs/GaAs quantum wells with higher Indium Content grown by molecular-beam expitaxy
Applied Physics Letters, 2005Co-Authors: Shiyong Zhang, Zhichuan Niu, Zheng Sun, Qin HanAbstract:High structural and optical quality 1.3 mu m GaInNAs/GaAs quantum well (QW) samples with higher (42.5%) Indium Content were successfully grown by molecular-beam epitaxy. The cross-sectional transmission electron microscopy measurements reveal that there are no structural defects in such high Indium Content QWs. The room-temperature photoluminescence peak intensity of the GaIn0.425NAs/GaAs (6 nm/20 nm) 3QW is higher than, and the full width at half maximum is comparable to, that of In0.425GaAs/GaAs 3QW, indicating improved optical quality caused by strain compensation effect of introducing N to the high Indium Content InGaAs epilayer. (C) 2005 American Institute of Physics.
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high structural and optical quality 1 3 mu m gainnas gaas quantum wells with higher Indium Content grown by molecular beam expitaxy
Applied Physics Letters, 2005Co-Authors: Shiyong Zhang, Zhichuan Niu, Zheng Sun, Qin HanAbstract:High structural and optical quality 1.3 mu m GaInNAs/GaAs quantum well (QW) samples with higher (42.5%) Indium Content were successfully grown by molecular-beam epitaxy. The cross-sectional transmission electron microscopy measurements reveal that there are no structural defects in such high Indium Content QWs. The room-temperature photoluminescence peak intensity of the GaIn0.425NAs/GaAs (6 nm/20 nm) 3QW is higher than, and the full width at half maximum is comparable to, that of In0.425GaAs/GaAs 3QW, indicating improved optical quality caused by strain compensation effect of introducing N to the high Indium Content InGaAs epilayer. (C) 2005 American Institute of Physics.
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High-Indium-Content InxGa1−xAs/GaAs quantum wells with emission wavelengths above 1.25 μm at room temperature
Applied Physics Letters, 2004Co-Authors: Zhichuan Niu, Wei Zhang, X. Wei, L. F. Bian, Qin HanAbstract:High-Indium-Content InxGa1-xAs/GaAs single/multi-quantum well (SQW/MQW) structures have been systematically investigated. By optimizing the molecular-beam epitaxy growth conditions, the critical thickness of the strained In0.475Ga0.525As/GaAs QWs is raised to 7 nm, which is much higher than the value given by the Matthews and Blakeslee model. The good crystalline quality of the strained InGaAs/GaAs MQWs is proved by x-ray rocking curves. Photoluminescence measurements show that an emission wavelength of 1.25 mum at room temperatures with narrower full width at half maximum less than 30 meV can be obtained. The strain relaxation mechanism is discussed using the Matthews-Blakeslee model. (C) 2004 American Institute of Physics.
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high Indium Content inxga1 xas gaas quantum wells with emission wavelengths above 1 25 μm at room temperature
Applied Physics Letters, 2004Co-Authors: Zhichuan Niu, Wei Zhang, X. Wei, L. F. Bian, Qin HanAbstract:High-Indium-Content InxGa1-xAs/GaAs single/multi-quantum well (SQW/MQW) structures have been systematically investigated. By optimizing the molecular-beam epitaxy growth conditions, the critical thickness of the strained In0.475Ga0.525As/GaAs QWs is raised to 7 nm, which is much higher than the value given by the Matthews and Blakeslee model. The good crystalline quality of the strained InGaAs/GaAs MQWs is proved by x-ray rocking curves. Photoluminescence measurements show that an emission wavelength of 1.25 mum at room temperatures with narrower full width at half maximum less than 30 meV can be obtained. The strain relaxation mechanism is discussed using the Matthews-Blakeslee model. (C) 2004 American Institute of Physics.
John Dallesasse - One of the best experts on this subject based on the ideXlab platform.
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physical model for high Indium Content ingan gan self assembled quantum dot ridge waveguide lasers emitting at red wavelengths λ 630 nm
Optics Express, 2015Co-Authors: Guanlin Su, Thomas Frost, Pallab Bhattacharya, John DallesasseAbstract:We present a physical model for recently demonstrated high Indium Content self-assembled In0.4Ga0.6N/GaN quantum dot (QD)-based ridge-waveguide lasers emitting at red wavelengths. The strain distribution in the QD is calculated using linear elastic theory with the application of shrink-fit boundary condition at the InGaN/GaN material interface, and the electronic states are evaluated using a single-band effective mass Hamiltonian. A Schrodinger-Poisson self-consistent solver is used to describe the effect of charge screening under current injection. Our theoretical result shows a good match to the measured Hakki-Paoli gain spectrum. Combining the calculated gain spectrum and cavity properties, we have developed a device-level simulation to successfully explain the electrical and optical characteristics of this specific laser. Possible solutions to improving the device performance have been explored.
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Physical model for high Indium Content InGaN/GaN self-assembled quantum dot ridge-waveguide lasers emitting at red wavelengths (λ ~ 630 nm).
Optics express, 2015Co-Authors: Thomas Frost, Pallab Bhattacharya, John DallesasseAbstract:We present a physical model for recently demonstrated high Indium Content self-assembled In0.4Ga0.6N/GaN quantum dot (QD)-based ridge-waveguide lasers emitting at red wavelengths. The strain distribution in the QD is calculated using linear elastic theory with the application of shrink-fit boundary condition at the InGaN/GaN material interface, and the electronic states are evaluated using a single-band effective mass Hamiltonian. A Schrodinger-Poisson self-consistent solver is used to describe the effect of charge screening under current injection. Our theoretical result shows a good match to the measured Hakki-Paoli gain spectrum. Combining the calculated gain spectrum and cavity properties, we have developed a device-level simulation to successfully explain the electrical and optical characteristics of this specific laser. Possible solutions to improving the device performance have been explored.
Jihui Yang - One of the best experts on this subject based on the ideXlab platform.
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optical and structural characteristics of high Indium Content ingan gan multi quantum wells with varying gan cap layer thickness
Journal of Applied Physics, 2015Co-Authors: Jihui Yang, D S Jiang, Degang Zhao, Ping Chen, Jiejie Zhu, Z S Liu, Junkai Liu, H Yang, Y T ZhangAbstract:The optical and structural properties of InGaN/GaN multi-quantum wells (MQWs) with different thicknesses of low temperature grown GaN cap layers are investigated. It is found that the MQW emission energy red-shifts and the peak intensity decreases with increasing GaN cap layer thickness, which may be partly caused by increased floating Indium atoms accumulated at quantum well (QW) surface. They will result in the increased interface roughness, higher defect density, and even lead to a thermal degradation of QW layers. An extra growth interruption introduced before the growth of GaN cap layer can help with evaporating the floating Indium atoms, and therefore is an effective method to improve the optical properties of high Indium Content InGaN/GaN MQWs.
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Optical and structural characteristics of high Indium Content InGaN/GaN multi-quantum wells with varying GaN cap layer thickness
Journal of Applied Physics, 2015Co-Authors: Jihui Yang, L. C. Le, X. G. He, J. J. Zhu, D S Jiang, D G Zhao, X J Li, P. Chen, J. P. LiuAbstract:© 2015 AIP Publishing LLC.The optical and structural properties of InGaN/GaN multi-quantum wells (MQWs) with different thicknesses of low temperature grown GaN cap layers are investigated. It is found that the MQW emission energy red-shifts and the peak intensity decreases with increasing GaN cap layer thickness, which may be partly caused by increased floating Indium atoms accumulated at quantum well (QW) surface. They will result in the increased interface roughness, higher defect density, and even lead to a thermal degradation of QW layers. An extra growth interruption introduced before the growth of GaN cap layer can help with evaporating the floating Indium atoms, and therefore is an effective method to improve the optical properties of high Indium Content InGaN/GaN MQWs.
