Transmission-mode GaN photocathode based on graded Al_xGa_(1-x)N buffer layer

作     者：杜晓晴 常本康 钱芸生 高频 

作者机构：Key Laboratory of Optoelectronic Technology and Systems of Ministry of Education of ChinaCollege of Optoelectronic EngineeringChongqing University Institute of Electronic Engineering and Opto-Electric TechnologyNanjing University of Science and Technology 

出 版 物：《Chinese Optics Letters》 (中国光学快报（英文版）)

年 卷 期：2011年第9卷第1期

页      面：17-20页

核心收录：

学科分类：080901[工学-物理电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 

基　　金：supported by the National Natural Science Foundation of China under Grant No.60701013 

主　　题：Buffer layers Epitaxial layers Field emission cathodes Gallium nitride Optical waveguides Photocathodes 

摘      要：We create a GaN photocathode based on graded AlxGa1-xN buffer layers to overcome the influence of buffer-emission layer interface on the photoemission of transmission-mode GaN photocathodes. A gate- shaped spectral response with a 260-nm starting wavelength and a 375-nm cut-off wavelength is obtained. Average quantum efficiency is 15% and short wavelength responses are almost equivalent to long wavelength ones. The fitted interface recombination velocity is 5×10^4 cm/s, with negligible magnitude, proving that the design of the graded buffer layers is efficient in obtaining good interface quality between the buffer and the emission laver.