RF-MBE Grown AlGaN/GaN HEMT Structure with High Al Content

A Si doped AlGaN/GaN HEMT structure with high Al content (x= 44%) in the barrier layer is grown on sapphire substrate by RF-MBE. The structural and electrical properties of the heterostructure are investigated by the triple axis X-ray diffraction and Van der Pauw-Hall measurement, respectively. The observed prominent Bragg peaks of the GaN and AlGaN and the Hall results show that the structure is of high quality with smooth interface.fabricated and characterized. Better DC characteristics, maximum drain current of 1.0A/mm and extrinsic transconductance of 218mS/mm are obtained when compared with HEMTs fabricated using structures with lower Al mole fraction in the AlGaN barrier layer. The results suggest that the high Al content in the AlGaN barrier layer is promising in improving material electrical properties and device performance.

High Power 940 nm Al-free Active Region Laser Diodes and Bars with a Broad Waveguide

The 940 nm Al-free active region laser diodes and bars with a broad waveguide were designed and fabricated. The stuctures were grown by metal organic chemical vapour deposition. The devices show excellent performances. The maximum output power of 6.7 W in the 100 f^m broad-area laser diodes has been measured, and is 2. 5 times higher than that in the Al-containing active region laser diodes with a narrow waveguide and 1. 7 times higher than that in Al-free active region laser diodes with a narrow waveguide. The 19 % fill-factor laser diode bars emit 33 W, and they can operate at 15W with low degradation rates.

分子束外延生长Al掺杂n型ZnS_（1-x）Tex的类DX中心

应用光致发光(PL)、电容-电压(C-V)、深能级瞬态谱(DLTS)和光电导(PC)技术系统研究Al掺杂ZnS_(1-x)Te_x中与Al有关的类DX中心。实验结果表明，ZnS_(1-x)Te_x中存在与Ⅲ－Ⅴ族半导体DX中心相类似的性质。获得与Al有关的类DX中心光离化能E_i(～1.0eV和2.0eV)和发射势垒E_e(0.21eV和0.39eV)，这表明ZnS_(1-x)Te_x大晶格弛豫的出现是由类DX中心引起。

High Efficiency Al-Free 980 nm InGaAs/ InGaAsP/ InGaP Strained Quantum Well Lasers

于2010-11-23批量导入

Photocurrent Measurem entof Si_(1-x)Ge_x/Si Multiple Quantum Wells With Ion Im plantationand Therm al Annealing

于2010-11-23批量导入

分子束外延生长的n型Al掺杂ZnS_(1-x)Te_x深中心研究

应用电容-电压、光致荧光和深能级瞬态谱技术研究了分子束外延生长的n型Al掺杂ZnS_(1-x)Te_x外延层深中心。Al掺杂ZnS_(0.977)Te_(0.023)的光致荧光强度明显低于不掺杂的ZnS_(0.977)Te_(0.023),这表明一部分Al原子形成非辐射深中心。Al掺杂ZnS_(1-x)Te_x(x=0,0.017,0.04和0.046)的深能级瞬态傅里叶谱表明，Al引进导带下的0.21和0.39eV电子陷阱，Te除了作为材料合金的成分和等电子中心外，还涉及到一个电子陷阱的形成，其相对导带的能级位置随Te组分增加而减小。实验结果还表明仅有少量掺杂的Al原子形成非辐射中心，这说明Al对于Te组分范围内(x≤0.046)的ZnS_(1-x)Te_x外延层的确是一种非常好的施主杂质。

MOVPE生长Al（0.35）Ga（0.65）As/GaAs量子阱结构的光致发光

于2010-11-23批量导入

InxGa（1-x）As缓冲层上InyGa（1-y）As/（Al）GaA超晶格的光伏谱研究

于2010-11-23批量导入

GaAs/Al（0.3）Ga（0.7）As短周期超晶格中负微分电导效应的观察

于2010-11-23批量导入

1MeVSi＋衬底加温注入Al（0.3）Ca（0.7）As/GaAs超晶格和GaAs的晶格损伤研究

用卢瑟福背散射沟道技术研究了1MeVSi~+在衬底加温和室温下以不同剂量注入Al＿(0．3)Ga＿(0．7)As／GaAs超晶格和GaAs后的晶格损伤。在衬底加温下, 观察到Al＿(0．3)Ga＿(0．7)As／GaAs超晶格和GaAs都存在一个动态退火速率与缺陷产生速率相平衡的剂量范围, 以及两种速率失去平衡的临界剂量。用热尖峰与碰撞模型解释了晶格损伤积累与注入剂量和衬底温度的关系。

GaAs/Al（0.4）Ga（0.6）As多量子肼红外探测器光吸收计算

于2010-11-23批量导入

GaAs/Al（0.33）Ga（0.67）As短周期超晶格中能带不连续性随压力的变化

于2010-11-23批量导入

GaAs/Ga（0.7）Al（0.3）超晶格中场致激子峰展宽机制的研究

于2010-11-23批量导入

GaAs/Ga（0.7）Al（0.3）As短周期超晶格中的自电光双稳和多稳态效应

国家自然科学基金

含杂六角密积结构原子簇Al（12）M的电子结构

于2010-11-23批量导入