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21.
The application of the strain induced lateral ordering process to the strain-compensated (Ga0.22In0.78As)m (Ga0.22In0.78P)m short period superlattices is investigated. The superlattices have been grown at low temperatures by solid source molecular
beam epitaxy (MBE) on (001) InP. These superlattices have been used in multiquantum well heterostructures using InP as barriers.
The anisotropic polarization of photoluminescence shows the existence of lateral modulation. Dark-field images using the 220
reflection gives modulated contrast in the superlattice layers. High-resolution transmission electron microscopy shows local
variations of the interplanar spacing of the (200) planes as well as the angles they form with the (002) planes. 相似文献
22.
23.
Thermal properties of AlGaInP/GaInP MQW red LEDs are investigated by thermal measurements and analysis for different chip sizes and substrate thicknesses. To extract the thermal resistance (Rth), junction temperature (Tj) is experimentally determined by both forward voltage and electroluminescence (EL) emission peak shift methods. For theoretical thermal analysis, thermal parameters are calculated in simulation using measured heat source densities. The Tj value increases with increasing the injection current, and it decreases as the chip size becomes larger. The use of a thin substrate improves the heat removal capability. At 450 mA, the Tj values of 315 K and 342 K are measured for 500 × 500 μm2 LEDs with 110 μm and 350 μm thick substrates, respectively. For 500 × 500 μm2 LEDs with 110 μm thick substrate, the Rth values of 13.99 K/W and 14.89 K/W are obtained experimentally by the forward voltage and EL emission peak shift methods, respectively. The theoretically calculated value is 13.44 K/W, indicating a good agreement with the experimental results. 相似文献
24.
通过分析激光器的结构,优化设计了非对称宽波导激光器结构及外延生长条件。利用低压金属有机化合物气相淀积技术(LP-MOCVD)生长了高质量的InGaAsP/GaInP无铝应变量子阱外延材料,制作成808 nm高功率半导体激光器mini阵列,将其应用到1 064 nm全固态激光器中。20℃下,制作的808 nm,0.5 cm半导体激光器mini阵列,连续驱动电流50 A时输出功率达到50 W,最高光电转换效率达到53%。将该808 nm激光器mini阵列应用到全固态1 064 nm激光模组中,50 W,1 064 nm激光输出时,工作电流只有15 A。经过多于500 h老化以后,1 064 nm全固态激光器的功率衰减小于2%。 相似文献
25.
用MOCVD方法生长GaInP及其掺杂材料,并对Si的掺杂行为进行了较详细的研究。采用低温度冲层技术可有效地控制高温(>700℃)生长GaInP及其掺杂材料的组分,从而使得GaInP掺Si的电子浓度达8×1018cm-3。在此基础上,进行了GaInP发光二极管材料的生长,所得器件具有良好的I-V曲线。 相似文献
26.
Jong-Won Lee Alfred T. Schremer Dan Fekete James R. Shealy Joseph M. Ballantyne 《Journal of Electronic Materials》1997,26(10):1199-1204
GaInP has a direct bandgap for In concentrations higher than approximately 30%, and the band-lineup between GaInP and GaP
is type-II for In concentrations less than 60%. Therefore, in order to use GaInP as the active light-emitting layer in an
optoelectronic device grown on GaP, the strain induced by the lattice mismatch between GaInP and GaP has to be somehow managed
such that formation of crystal defects is suppressed. One method is to grow the layer thinner than the critical thickness.
Another method that recently received much attention is to grow strain-induced Stranski-Krastanov islands (sometimes referred
to as self-assembled quantum dots). Small droplets of highly latticmismatched materials have been embedded into single crystals
without generating defects such as threading dislocations and stacking faults using this method. We have grown a series of
GaInP/GaP layers by metalorganic chemical vapor deposition and have studied the light emission from them. Ordered GaInP islands
were found to be responsible for the light emission. We present the light emission characteristics of these ordered GaInP/GaP
islands, and their dependence on various growth parameters. 相似文献
27.
The conduction band alignment of compressively strained In1−xGaxP relative to lattice matched InGaP/GaAs has been determined by capacitance-voltage profil-ing. A modified version of Kroemer’s
capacitance-voltage profiling method is developed wherein a quantum well is profiled instead of a single heterojunction. A
one-dimensional Poisson-Schrodinger solver was used to fit the reconstructed carrier profiles corresponding to a value of
ΔEc at varying temperatures. Schottky barrier diode structures containing a single strained InGaP quantum well were grown by
low pressure metalorganic chemical vapor deposition. The two strained compositions studied contained 35 and 31% gallium. Conduction
band offsets of 101 and 131 meV were found for the 35 and 31% samples, respectively, with an estimated accuracy of ±5 meV.
These results agreed closely with values predicted by empirical calculations. 相似文献
28.
文章首先重点介绍了国内外开展GaInP/GaAs/Ge三结太阳电池的电子、质子及其他辐射粒子或射线辐照实验的研究进展,然后从辐照损伤效应的仿真模拟研究、抗辐射加固技术、损伤预估方法等方面综述了GaInP/GaAs/Ge三结太阳电池辐照损伤效应及加固技术的研究进展,最后梳理了当前GaInP/GaAs/Ge三结太阳电池辐照损伤效应研究中亟待解决的关键技术问题,为深入开展GaInP/GaAs/Ge三结太阳电池辐照损伤效应实验方法标准制定、损伤机理分析、在轨寿命预估及抗辐射加固技术研究提供了理论指导和实验技术支持。 相似文献
29.
Takashi Kita Akira Fujiwara Hiroshi Nakayama Taneo Nishino 《Journal of Electronic Materials》1996,25(5):661-665
Photocurrent anisotropy of long-range ordered Ga0.5In0.5P alloys has been sys-tematically investigated. The ordered Ga0.5In0.5P is a compositional modulated superlattice of Ga0.5+η/2In0.5-η/2P and Ga0.5-η/2In0.5+η/2P monolayer planes, where η is a long-range order parameter. The photocurrent edge of the [110] polarization is lower than
that of the
. The observed anisotropy in the photocurrent spectra is due to a crystal-field splitting at the valence-band maximum in ordered
Ga0.5In0.5P. The anisotropy shows a continous variation as a function of η. In order to make clear the effects of the valence-band splitting
on the polarized photocurrent spectra, we performed theoretical calculations in which a distribu-tion of η in the epitaxial
film and an order-parameter dependence of oscillator strength were considered. From these calculations, it is found that oscillator
strength is a key parameter in the anisotropic character. The calculated results moderately agree with the measured data.
Furthermore, the epitaxial thickness dependence of the anisotropic character in photocurrent was investigated. 相似文献
30.
以实现宽谱减反介质复合纳米结构表面的高 效单结GaInP太阳电池为目标,利用严格耦合波分析理论, 仿真研究了该电池表面的介质复合纳米结构对太阳电池宽谱减反、归一化吸收、最大化理想 效率的影响。该介质复 合纳米结构从上往下依次为SiO2纳米锥、SiO2介质层和SiNx介质层,通过对SiO2纳米锥占空比、深宽比以及对SiO2和SiNx介质层厚度等参数的系列仿真最终优化出适用于单结Ga InP电池的表面结构。结果表明:当SiO2纳米锥底部 直径D=550nm、高度H=650 nm、SiN x介质层厚度为60 nm时电池具有最高的 最大化理想转换效率为28.58%。上述结果为后期实验以及该类电池 实现规模化生产奠定了基础。 相似文献