Improved electron capture capability of field-assisted exponential-doping GaN nanowire array photocathode

作     者：Lei Liu Feifei Lu Sihao Xia Yu Diao Jian Tian Lei Liu;Feifei Lu;Sihao Xia;Yu Diao;Jian Tian

作者机构：Department of Optoelectronic TechnologySchool of Electronic and Optical EngineeringNanjing University of Science and TechnologyNanjing 210094China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2020年第42卷第7期

页      面：54-62页

核心收录：

学科分类：081702[工学-化学工艺] 07[理学] 070205[理学-凝聚态物理] 08[工学] 0817[工学-化学工程与技术] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：This work was supported financially by the Qing Lan Project of Jiangsu Province,China(No.2017-AD41779) the Fundamental Research Funds for the Central Universities-China(No.30916011206) the Six Talent Peaks Project in Jiangsu Province,China(No.2015-XCL-008) 

主　　题：Exponential-doping GaN nanowire array Photocathode Field-assisted Quantum efficiency Electrons collection 

摘      要：The exponential-doping GaN nanowire arrays(GaN NWAs)photocathode has alight-trapping effect,and the built-in electric field can promote the concentration of the photogene rated carrier center to the top surface of the ***,in the preparation ofactual NWAs photocathodes,the problem that photons emitted from the sides of the nanowires cannot be effectively collected has been *** proposed field-assisted exponential-doping GaN NWAs can bend the motion trajectory of the emitted electrons toward the collecting *** this study,the quantum efficiency(QE)and collection efficiency(CE)of the external field-assisted exponential-doping GaN NWAs photocathode are derived based on the two-dimensional carrier diffusion equation and the initial energy and angular distribution,*** a field-assisted exponential-doping GaN NWAs with a width d=200 nm and a height H=400 nm,the optimal structural parameters are obtained:the incident angleθ=50°and the nanowire spacing is L=335.6 *** this basis,the field intensity of 0.5 V/μm can maximize the CE of the *** the results show that the field-assisted approach does contribute to the collection of emitted electrons,which can provide theoretical guidance for high-performance electron sources based on exponential-doping GaN NWAs *** field-assisted exponential-doping GaN NWAs cathode is expected to be verified by the experimental results in the future.