Temporal response of laminated graded-bandgap GaAs-based photocathode with distributed Bragg reflection structure:Model and simulation  

作　　者：Zi-Heng Wang Yi-Jun Zhang Shi-Man Li Shan Li Jing-Jing Zhan Yun-Sheng Qian Feng Shi Hong-Chang Cheng Gang-Cheng Jiao Yu-Gang Zeng 王自衡;张益军;李诗曼;李姗;詹晶晶;钱芸生;石峰;程宏昌;焦岗成;曾玉刚(School of Electronic and Optical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China;National Key Laboratory of Science and Technology on Low-Level-Light,Xi'an 710065,China;Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China)

机构地区：[1]School of Electronic and Optical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China [2]National Key Laboratory of Science and Technology on Low-Level-Light,Xi'an 710065,China [3]Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China

出　　处：《Chinese Physics B》2022年第9期628-635,共8页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.U2141239 and 61771245);the Fund from the Science and Technology on Low-Light-Level Night Vision Laboratory of China(Grant No.J20200102).

摘　　要：To describe the dynamic response characteristics of the laminated graded-bandgap GaAs-based photocathode with distributed Bragg reflection structure,a general theoretical temporal response model is deduced by combining the unsteady continuity equation and numerical calculation method.Through the model,the contribution of the distribution Bragg reflec-tion structure and graded-bandgap emission layer to the temporal response are investigated.Meanwhile,the relationships between the temporal response characteristics of the laminated GaAs-based photocathode and different structural parame-ters are also analyzed,including average electron decay time,emission layer thickness,and incident light wavelength.It is found that the introduction of distribution Bragg reflection(DBR)layer solves the discrepancy between the absorption capability of the emission layer and the temporal response.Moreover,the distributed Bragg reflection layer can improve the time response by optimizing the initial photoelectron distribution.The improvement effect of the DBR layer on the temporal response is enhanced with the emission layer thickness decreasing or the incident light wavelength increasing.These results explain the effect of the DBR layer of the photocathode on the dynamic characteristics,which can offer a new insight into the dynamic research of GaAs-based photocathode.

关 键 词：temporal response GaAs-based photocathode distribution Bragg reflection graded-bandgap 

分 类 号：O469[理学—凝聚态物理]