蓝绿敏感变组分变掺杂多层结构AlGaAs/GaAs阴极光电发射机理研究

项目名称： 蓝绿敏感变组分变掺杂多层结构AlGaAs/GaAs阴极光电发射机理研究

项目编号： No.61308089

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 陈亮

作者单位： 中国计量学院

项目金额： 28万元

中文摘要： 蓝绿敏感AlGaAs/GaAs光电阴极采用Al组分和掺杂浓度由体内向表面逐渐降低的变组分变掺杂的方法，形成从内到外的可变能带结构，从而使光生电子以电场漂移和浓度扩散双重方式向表面输运。本项目利用第一性原理研究变组分变掺杂结构材料的能带结构，建立变组分变掺杂结构材料的稳态光电压谱模型和量子效率模型，借助瞬态浓度光栅和稳态光电压谱实现对阴极材料性能的复合评价分析，并和阴极材料激活后的量子效率曲线进行对比研究实现对光生电子隧穿表面势垒层的表面电子逸出几率曲线的准确拟合，从而构建阴极材料激活前后的闭环评价体系。利用该闭环评价体系，开展变组分变掺杂结构优化设计、表面势垒隧穿机理分析和响应光谱调制等方面的研究。高性能蓝绿敏感AlGaAs/GaAs光电阴极在我国泥土和沙漠探测、海洋探潜、海底通信、海底成像等领域具有广泛的应用前景。

中文关键词： AlGaAs；光电阴极；第一性原理；光电压谱；量子效率

英文摘要： The sensitive to blue and green AlGaAs/GaAs photocathode will be prepared with varied Al composition and varied doping concentration by varied doping from body to surface in order to form a varied energy band for cathode material, thus the photo-excited electrons can transport to surface not only through concentration diffusion but also through electric field drift. This project will firstly carry out research on energy band of varied composition and doping concentration by first principles study, thus the models of steady-state photovoltage spectroscopy and quantum efficiency can be well established. The parameters of cathode materials will be composite evaluated by steady-state photovoltage spectroscopy and instantaneous concentration grating, furthermore the surface escaping probability for excited electrons to tunnel through surface barriers can be well fitted through the comparative research between composited evaluations before activation and quantum efficiency after activation. Finally this comparative research method can form a closed-loop research system for AlGaAs/GaAs photocathode and we can carry out research on optimal design of cathode materials、surface barriers tunneling mechanism、 spectral response band modulation and other aspects. High-performance extended blue AlGaAs/GaAs photocathode will hav

英文关键词： AlGaAs；Photocathode；First-principle；Surface spectroscopy；Quantum efficiency