[GaN(Mg)-Cs]:[O-Cs] model for the Negative Electron Affinity GaN (0001) surface

被引：9

作者：

Wang, Xiaohui ^{[1
]}

Zhang, Yijun ^{[2
]}

Yu, He ^{[1
]}

Wu, Jieyun ^{[3
]}

机构：

[1] Univ Elect Sci & Technol China, Sch Optoelect Informat, Chengdu 610054, Peoples R China

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

[3] Univ Elect Sci & Technol China, Sch Commun & Informat Engn, Chengdu 610054, Peoples R China

来源：

OPTIK | 2016年 / 127卷 / 19期

基金：

中国国家自然科学基金;

关键词：

Negative Electron Affinity; GaN Photocathode; Photoemission Model; ACTIVATION LAYER; ADSORPTION-KINETICS; ESCAPE PROBABILITY; GAAS PHOTOCATHODES; CS; GAAS(100); RECONSTRUCTIONS; INTERFACE; OXYGEN; AUGER;

D O I：

10.1016/j.ijleo.2016.05.140

中图分类号：

O43 [光学];

学科分类号：

070207 ; 0803 ;

摘要：

Because of the limitations of the existing Negative Electron Affinity (NEA) photocathode surface emission models, [GaN(Mg)-Cs]:[O-Cs] photoemission model based on dual-dipole model is established, which can explain the photoemission mechanism of the NEA GaN photocathode well. Cs, O adsorption process on the GaN (0001) surface during the activation is discussed, and the GaN(Mg)-Cs dipole layer is found having a unified direction which is conducive for photoelectron escaping, so photocurrent has a significant increase when Cs is introduced. There is not a unified direction for the O-Cs dipole layer. Because of the surface defects, part of the O-Cs dipoles have the direction which is conducive for photoelectron escaping, and the photocurrent has a modest growth after introducing O. Finally, the performance of GaN and GaAs photocathode are compared based on the photoemission model, and the reason of better stability of NEA GaN photocathode is interpreted. (C) 2016 Elsevier GmbH. All rights reserved.

引用

页码：7611 / 7624

页数：14