title: [Comparative study of uniform-doping and gradient-doping negative electron affinity GaN photocathodes].
abstract: High temperature annealing and Cs/O activation are external incentives, while the property of GaN material is internal factor in the preparation of negative electron affinity GaN photocathode. The similarities and differences of the performance of the two structure photocathodes are analysed based on the difference of the structure between uniform-doping and gradient-doping negative electron affinity GaN photocathodes and the changes in photocurrents in activation and the quantum yield after successfully activated of GaN photocathodes. Experiments show that: the photocurrent growth rate is slower in activation, activation time is longer and quantum efficiency is higher after successfully activated of gradient-doping GaN photocathode than those of uniform-doping photocathode respectively. The field-assisted photocathode emission model can explain the differences between the two, built-in electric field of gradient-doping structure creates additional electronic drift to the photocathode surface, and the probability of electrons to reach the photocathode surface is improved correspondingly.
authors: Institute of Electronic Engineering and Optoelectronic Technology, Nanjing University of Science and Technology, Nanjing 210094, China. libiao2006@126.com
authors: Biao
authors: B
authors: Li
authors: Ben-Kang
authors: BK
authors: Chang
authors: Yuan
authors: Y
authors: Xu
authors: Xiao-Qing
authors: XQ
authors: Du
authors: Yu-Jie
authors: YJ
authors: Du
authors: Xiao-Qian
authors: XQ
authors: Fu
authors: Xiao-Hui
authors: XH
authors: Wang
authors: Jun-Ju
authors: JJ
authors: Zhang