Improvement of photoemission performance of a gradient-doping transmission-mode GaAs photocathode

被引：8

作者：

Zhang Yi-Jun ^{[1
]}

Niu Jun ^{[1
]}

Zhao Jing ^{[1
]}

Xiong Ya-Juan ^{[1
]}

Ren Ling ^{[1
]}

Chang Ben-Kang ^{[1
]}

Qian Yun-Sheng ^{[1
]}

机构：

[1] Nanjing Univ Sci & Technol, Inst Elect Engn & Optoelect Technol, Nanjing 210094, Jiangsu, Peoples R China

来源：

CHINESE PHYSICS B | 2011年 / 20卷 / 11期

基金：

中国国家自然科学基金;

关键词：

transmission-mode photocathode; gradient-doping; Cs-O activation; quantum yield; NEGATIVE ELECTRON-AFFINITY; MOLECULAR-BEAM EPITAXY; P-TYPE GAAS; CARRIER CONCENTRATION; DIFFUSION LENGTH; SURFACES; ACTIVATION; EMISSION; BAND;

D O I：

10.1088/1674-1056/20/11/118501

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Two types of transmission-mode GaAs photocathodes grown by molecular beam epitaxy are compared in terms of activation process and spectral response, one has a gradient-doping structure and the other has a uniform-doping structure. The experimental results show that the gradient-doping photocathode can obtain a higher photoemission capability than the uniform-doping one. As a result of the downward graded band-bending structure, the cathode performance parameters, such as the electron average diffusion length and the surface electron escape probability obtained by fitting quantum yield curves, are greater for the gradient-doping photocathode. The electron diffusion length is within a range of from 2.0 to 5.4 mu m for doping concentration varying from 10(19) to 10(18) cm(-3) and the electron average diffusion length of the gradient-doping photocathode achieves 3.2 mu m.

引用

页数：7

共 30 条

[1] GAAS PHOTO-CATHODES FOR LOW LIGHT LEVEL IMAGING [J].