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排序方式: 共有91条查询结果,搜索用时 15 毫秒
1.
新型红光LED中ITO的特性研究   总被引:1,自引:1,他引:0  
用真空电子束蒸镀的方法制备半导体发光二极管LED 所用的ITO(indium tin oxide)膜。利用TLM(transmission line model)研究ITO与GaP接触特性。在氮气环境,435℃条件下,快速热退火40s能获得最小的接触电阻4.3×10-3Ωcm2。Hall测试和俄偈电子能谱表明,影响接触电阻的主要原因是ITO载流子浓度的改变和In,Ga,O的扩散。另外,制作了以300nm ITO为窗口层的新型AlGaInP红光LED并研究其可靠性。发现ITO的退化导致了LED的电压持续升高。而ITO与GaP热膨胀系数的不同导致了LED的最终失效。  相似文献   
2.
MOVPE-preparation of highly ordered InP(100) and GaP(100) surfaces was monitored with in-situ reflectance difference spectroscopy (RDS). Specific ordered P-terminated and ordered cation-terminated surface reconstructions were identified with specific structured RD spectra with the highest peaks. After contamination-free transfer of the samples to UHV, RDS measurements were performed also at 20 K. The experimental RD spectrum for the In-terminated, (2×4) reconstructed InP(100) surface shows a remarkable similarity to a recently published theoretical spectrum, whereas there is only moderate similarity between the experimental RD spectrum for the (2×4) reconstructed Ga-terminated GaP(100) surface and a recently proposed theoretical spectrum.  相似文献   
3.
GaP∶N绿色LED发光效率的提高有赖于对其结构参数的优化。 根据载流子分布的连续性, 由泊松方程自洽求解, 得出了半导体n~--n结势垒分布的计算方法。 在此基础上,计入n~-区内的电位降, 计算了商用发光二极管p~ -n~--n结构的势垒分布, 为整体结构的参数优化准备了必要的条件。  相似文献   
4.
GaAs、GaP、InP、InGaAsP、AlGaAs、InAlGaAs的化学腐蚀研究   总被引:2,自引:0,他引:2  
为研制全集成光开关、微片式激光器等,对GaAs、GaP、InGaAsP、InAIGaAs、AlGaAs等材料的化学腐蚀进行了实验研究。为了研制InAlGaAs/InAlAs/InAlGaAs微片式激光器,开发了H3PO4/H2O2/H2O薄层腐蚀液和HCl/H2O选择性腐蚀液;为了研制InGaAsP/InP/InGaAsPTbar型光波导,开发了HCl/H3PO4/H2O2薄层腐蚀液和HCl/H2O2选择性腐蚀液;为了研制GaP、InGaP光波导,开发了HCl/HNO3/H2O薄层腐蚀液。它们都具有稳定、重复性好、速率可控、腐蚀后表面形貌好等特点。除此之外,蚀刻成的GaP光波导侧壁平滑无波纹起伏。此种结果尚未见报导。  相似文献   
5.
经高温热处理后的 SiGe∶GaP 半导体温差电材料,其微观结构由具有富 Si 相特征变化成为具有富 Ge 相特征,温差电优值也得到了提高。实验还表明,材料晶格热导率的降低与富 Si 相的消失和富 Ge相的出现有关。然而,塞贝克系数和电导率的显著变化却与微观结构中富 Si 相和富 Ge 相的变化基本无关。通过对材料微观结构和温差电特性比较发现,具有富 Ge 相特征的微观结构对应于较大的温差电优值。  相似文献   
6.
Photocapacitance (PHCAP) measurements have been carried out on GaP crystals grown by the liquid-encapsulated Czochralski (LEC) method with heat treatment under various phosphorus-vapor pressures at different temperatures. Electron traps of EC−1.1 eV, EC−1.6 eV, EC−1.9 eV, and a hole trap of EV+2.26 eV are mainly detected. The phosphorus-vapor pressure dependence of the EC−1.9 eV trap density and their diffusion behavior indicate that they are interstitial phosphorus atoms. The densities of both EC−1.1 eV and EC−1.6 eV traps are strongly dependent on the shallow impurity concentrations. Moreover, the density of EC−1.1 eV traps increases with increasing phosphorus-vapor pressure. From these results, we suggest that EC−1.1 eV traps are the complexes of shallow donors and antisite phosphorus atoms. Deep-level densities in GaP crystals after annealing at 860°C or 960°C for 60 min are decreased almost one order of magnitude lower than those in untreated substrate crystals, which should have occurred via out-diffusion of interstitial phosphorus atoms. However, such an effect is not prominent for 800°C treatment for 60 min.  相似文献   
7.
张福甲  刘凤敏 《半导体光电》1997,18(6):375-379,425
介绍了间接跃迁的半导体AlP与GaP形成的超晶格,由于零折叠效应,实现了能带由间接带隙向直接带隙的转变,从而增加了带间的光跃迁几率,并推导了该几率的表达式。  相似文献   
8.
GaP:(N)的背景光谱和发光尖峰   总被引:1,自引:0,他引:1  
获得高分辨GaP(N)光致发光光谱,观察到等电子陷陆束缚激子发光中LO和loc多声子发射,其强度分布答合泊松分布。将声子伴带区分为直接光跃迁和间接光跃迁,并进行了相应讨论,还观察到局域声子效应--光谱相似定律和相当显著的背景光谱。  相似文献   
9.
The effect of nitrogen doping on the 300°K quantum efficiency and luminescence spectra of VPE-grown gallium phosphide has been investigated. The range of nitrogen concentrations studied was 2 × 1018 –1.5 × 1019 cm{−3 on the corrected Lightowlers scale. Over this range, the external quantum efficiency of contactless dice at 40 amp/cm2 in air varied from 0.04% to 0.13%, increasing monotonically with increasing nitrogen concentration. The photoluminescence spectra from as-grown epi layers and the electroluminescence spectra of contacted dice in reflecting cups were compared, and were characterized by the parameters lumens/watt, radiometric center of gravity, and photometric center of gravity. The relationship of these parameters to each other and their variation with nitrogen concentration in GaP has been determined. The problem of filtering the spectra to obtain greener devices with acceptable brightness has been investi-gated using the transmission spectra of two specific filters.  相似文献   
10.
The degradation of light output with operating time has been studied for nitrogen doped GaP light emitting diodes fabricated from vapor phase epitaxial material. The degradation is found to saturate at a non-zero value of efficiency. The process is characterized in terms of a degradation rate constant and the saturation value of efficiency. The rate is found to be a strong function of current density during operation and to a lesser degree materials parameters such as dislocation density. The saturation value appears to be independent of these parameters. The degradation is specifically associated with a decrease in the minority carrier lifetime in the p-side of these diffused LEDs. A model for the generation of non-radiative recombination centers which describes the degradation process quantitatively is presented.  相似文献   
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