变掺杂变组分Al_(x)Ga_(1–x)As/GaAs反射式光电阴极分辨力特性  

Resolution characteristics of varying doping and varying composition Al_(x)Ga_(1–x) As/GaAs reflective photocathodes

作　　者：邓文娟[1,2] 朱斌 王壮飞 彭新村[1,2] 邹继军[1] Deng Wen-Juan;Zhu Bin;Wang Zhuang-Fei;Peng Xin-Cun;Zou Ji-Jun(Engineering Research Center of Nuclear Technology Application(East China University of Technology),Ministry of Education,Nanchang 330013,China;Jiangxi Province Engineering Research Center of New Energy Technology and Equipment,East China University of Technology,Nanchang 330013,China)

机构地区：[1]东华理工大学,核技术应用教育部工程研究中心,南昌330013 [2]东华理工大学,江西省新能源工艺及装备工程技术中心,南昌330013

出　　处：《物理学报》2022年第15期265-271,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61961001,11875012,62061001,61771245);江西省自然科学基金(批准号:20181BAB202026,20192ACBL20003,20202BAB202013,20203BBE53030);江西省“双千计划”(批准号:jxsq2019201053)资助的课题。

摘　　要：根据建立的变掺杂变组分反射式Al_(x)Ga_(1–x)As/GaAs光电阴极的分辨力模型以及调制传递函数(MTF)理论模型,仿真了材料中掺杂浓度线性变化、Al组分线性变化,掺杂浓度均匀不变、Al组分线性变化,掺杂浓度线性变化、Al组分均匀不变,掺杂浓度均匀不变、Al组分均匀不变这4种不同结构反射式光电阴极的分辨力特性.分析了Al组分、掺杂浓度、Al_(x)Ga_(1–x)As层厚度、GaAs层厚度和入射光波长对阴极分辨力的影响.仿真结果表明,阴极材料中掺杂浓度梯度变化以及Al组分梯度变化都可以提高反射式Al_(x)Ga_(1–x)As/GaAs光电阴极的分辨力,其中掺杂浓度线性变化的同时,Al组分线性变化对Al_(x)Ga_(1–x)As/GaAs光电阴极分辨力的影响最为明显.仿真结果还表明:Al组分从0.45线性变化至0时,阴极分辨力最好;掺杂浓度从1019—1018 cm^(–3)线性变化比保持1019 cm^(–3)不变,阴极分辨力更好;而阴极中Al_(x)Ga_(1–x)As、GaAs层厚度以及入射光波长对4种阴极分辨力的影响则有着不同的变化规律.According to the established resolution model and modulation transfer function(MTF) of varying doping and varing composition reflection-mode(r-mode) Al_(x)Ga_(1–x) As/GaAs photocathode,the resolutions of four types of r-mode photocathodes,i.e.linearly varying doping and linearly varying Al composition,uniform doping and linearly varying Al composition,linearly varying doping and uniform Al composition,uniform doping and uniform Al composition structures,are simulated,and the effects of Al composition,the types of doping,Al_(x)Ga_(1–x) As layer thickness,GaAs layer thickness,and incident light wavelength on the resolution of cathodes are analyzed.The simulation results indicate that the varying doping and varying band-gap structures can also upgrade the resolution for r-mode Al_(x)Ga_(1–x) As/GaAs photocathodes,and the effect of linearly varying doping and linearly varying composition structure are more pronounced.The simulation results also show that the MTFs of the cathodes with the Al composition varying from 0.45 to 0 linearly declining are highest.The MTFs of the cathodes with the linearly varying doping from 1019-1018 cm–3 are higher than that with uniform 1019 cm–3doping.With the increase of Al_(x)Ga_(1–x) As thickness,GaAs thickness and incident light wavelength,the MTFs of four types photocathode have different regularities.

关 键 词：变掺杂变组分 调制传递函数 内建电场 分辨力 

分 类 号：O462[理学—电子物理学]