摘要:
用金属有机物化学气相沉积法外延制备了一个透射式蓝延伸GaAs光电阴极,积分灵敏度达到1980μA/lm,同时与美国ITT公司的一条蓝延伸阴极光谱响应曲线对比,分别对两者进行了光学结构拟合.结果表明,国内阴极在Ga_（1-x）Al_xAs层厚度、A1组分、电子扩散长度和后界面复合速率上与国外存在差距,这导致国内阴极的蓝延伸性能不及国外.国内蓝延伸阴极的表面电子逸出几率、发射层厚度与国外阴极拟合结果一致,这使得两者长波响应性能差别远小于短波部分的差别.另外响应波段全谱的吸收率小于国外阴极,导致国内透射式蓝延伸GaAs光电阴极光谱响应、积分灵敏度尚不及国外.
Abstract:
One transmission-mode extended blue GaAs photocathode is prepared by MOCVD,whose integral sensitivity is 1980μA/lm.Its spectral curve is compared with the spectral curve of ITT photocathode for analyzing optical structure.The comparison indicates that the differences lie in the thickness and the Al mole value of the Ga_（1-x）Al_x As window layer,electron diffusion length,and back-interface recombination velocity,which make the photocathode in this experiment inferior to that of ITT in extended blue performance.However our surface electron-escape probability and the thickness of the GaAs active layer are in accordance with those of ITT,which leads their difference in the long waveband part to be less than in the short one.In addition,our absorptivity in the whole response waveband is smaller than that of ITT photocathode,which leads the spectral response and integral sensitivity of the domestic transmission-mode extended blue GaAs photocathode to be inferior to the exotic one.
首页
登录
注册
下载: