发射层对指数掺杂Ga_(1-x)Al_xAs/GaAs光阴极性能的影响  

Influence of the Active Layer on Exponential-Doping Ga_(1-x)Al_xAs/GaAs Photocathode Performances

作　　者：赵静[1] 常本康[1] 熊雅娟[1] 张益军[1] 张俊举[1] 

机构地区：[1]南京理工大学电子工程与光电技术学院,南京210094

出　　处：《电子器件》2011年第2期119-124,共6页Chinese Journal of Electron Devices

基　　金：国家自然科学基金项目(60678043);南京理工大学自主科研专项计划课题资助项目(2010ZYTS032)

摘　　要：为了探索发射层厚度对指数掺杂Ga1-xAlxAs/GaAs光电阴极光学性能与光电发射性能的影响,实验制备了两种发射层厚度不同的阴极样品,并测试得到400μm～1 000 nm内反射率、透射率与光谱响应曲线。实验结果说明发射层2.0μm厚的样品比1.6μm厚的样品性能更好。利用薄膜光学矩阵理论公式计算阴极膜系反射率、透射率、吸收率与发射层厚度的关系公式,并对原有的量子效率公式进行光谱反射率和短波截止限的修正。用修正后的公式仿真不同发射层厚度下光阴极吸收率与光谱响应曲线,指出发射层厚度对阴极光学性能与光电发射性能的不同影响。进一步计算得到指数掺杂的Ga1-xAlxAs/GaAs光电阴极最佳发射层厚度范围是1.8μm～2.4μm。For research on the influence of the active layer on optical and photoelectric performances of exponential-doping Ga1-xAlxAs/GaAs photocathode,we prepared two samples with different thicknesses of 1.6 μm and 2.0 μm for the active layer.The reflectance,transmittance and spectral response curves were measured ranging from 400 nm to 1000 nm.The experimental result showed that the thicker sample possesed better performance than the other one.Theoretical reflectance,transmittance and absorptivity are derived as functions of the thickness from matrix theory in thin film optics.And the original quantum efficiency formula is modified by reflectance spectrum and shortwave limit.Based on the modification,absorptivity and spectral response are simulated with various thicknesses.It illuminates that the influence of the active layer is inconsistent on both the performances.Additionally,the scope of the optimal thickness is calculated as 1.8 μm～2.4 μm in the case of exponential-doping Ga1-xAlxAs/GaAs photocathode.

关 键 词：光学薄膜 Ga1-xAxlAs/GaAs 光电阴极 光学性能 光电发射性能 光谱曲线 

分 类 号：O462.3[理学—电子物理学]