物理学报2024，Vol.73Issue(11)：368-376,9.DOI:10.7498/aps.73.20240253
532nm响应增强的AlGaAs光电阴极
AlGaAs photocathode with enhanced response at 532 nm
摘要
Abstract
The AlGaAs photocathode can be used in the field of underwater optical communication because of its fast response speed and adjustable spectral response range.In order to solve the problem that the low light absorption of the AlGaAs emission layer limits the improvement of its quantum efficiency,the distributed Bragg reflector(DBR)structure is used to reflect the light at a specific wavelength back to the emission layer to further increase the absorption rate,thus improving the response capability of the photocathode at 532 nm.The spectral response model of the AlGaAs photocathode with DBR structure is obtained by solving one-dimensional continuity equation.The optical model of the AlGaAs photocathode with enhanced response at 532 nm is established by the finite-difference time-domain method.The effects of the sublayer periodic pairs,the sublayer material and the thickness of emission layer and buffer layer on the absorption rate of emission layer are analyzed.The light absorption distributions of AlGaAs photocathode with and without DBR structure are compared,and the influence mechanism of DBR structure on the blue-green light absorption capacity of AlGaAs photocathode emission layer is clarified,which can provide a theoretical basis for designing its structural parameters.The results show that the DBR structure with a periodic pair of 20 and Al0.7Ga0.3As/AlAs has the best reflection effect on 532 nm light.Based on the DBR structure,when the thickness of the emission layer and buffer layer are 495 nm and 50 nm,respectively,the emission layer has the best absorption rate of 532 nm light.Furthermore,two kinds of AlGaAs photocathodes with and without DBR structure are prepared by the metal-organic chemical vapor deposition technology,and the reflectivity and profile structure of the grown samples are characterized.Then the Cs/O activation experiments are performed to compare the spectral response curves.It is found that the spectral response of the AlGaAs photocathode sample with DBR structure at 532 nm wavelength is about twice that of the sample without DBR structure.关键词
AlGaAs光电阴极/分布式布拉格反射镜/光谱响应/光吸收Key words
AlGaAs photocathode/distributed Bragg reflector/spectral response/optical absorption引用本文复制引用
王东智,钱芸生,曾玉刚,张益军,李诗曼,童泽昊,唐嵩,石峰,焦岗成,程宏昌,富容国..532nm响应增强的AlGaAs光电阴极[J].物理学报,2024,73(11):368-376,9.基金项目
国家自然科学基金(批准号:62271259,U2141239)、微光夜视技术重点实验室基金(批准号:J20220102)和江苏省研究生科研与实践创新计划(批准号:KYCX23_0431)资助的课题. Project supported by the National Natural Science Foundation of China(Grant Nos.62271259,U2141239),the Science and Technology on Low-Light-Level Night Vision Laboratory Foundation of China(Grant No.J20220102),and the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(Grant No.KYCX23_0431). （批准号:62271259,U2141239）
