NEA GaN光电阴极表面模型研究  

Study of NEA GaN photocathode surface model

作　　者：乔建良[1,2] 牛军[1,2] 杨智[1] 邹继军[1] 常本康[1] 

机构地区：[1]南京理工大学电子工程与光电技术学院,南京210094 [2]南阳理工学院电子与电气工程系,河南南阳473004

出　　处：《光学技术》2009年第1期145-147,151,共4页Optical Technique

基　　金：国家自然科学基金资助项目(60871012)

摘　　要：针对目前NEAGaN光电阴极研究中Cs激活或Cs/O激活后表面状态的形成过程还不清楚的问题,围绕NEAGaN光电阴极的光电发射机理,结合GaN光电阴极激活过程中出现的现象及成功激活的最终效果,给出了GaN光电阴极铯氧激活后的表面模型[GaN(Mg):Cs]:O-Cs。利用该模型可很好地解释单独用Cs激活时约-1.0eV的有效电子亲和势和Cs/O共同激活时-1.2eV的有效电子亲和势的成因,也较好地解释了表面吸附原子的组合形式,即Cs/O激活后激活层的化学结构由Cs2O2和CsO2构成。Aimming at the problem that the forming process of the surface state after Cs activation or Cs/O activation is still unknown during NEA GaN photocathode study at present, encircling the photoemission mechanism of NEA GaN photocathode, combining the experiment phenomena during the activation and the successful activation results, the GaN photocathode surface model [GaN（Mg）：Cs]： O-Cs after activation with cesium and oxygen is given. Using this model, the reasons that about - 1.0 eV effective electron affinity can be achieved after activation only with Cs and about 1.2 eV effective electron affinity can be achieved after activation with Cs/O can be explained well. The surface atom formation can also be explained well, namely the chemical construction of dipole layer after Cs/O activation should be formed by Cs2O2 and CsO2.

关 键 词：电子技术 表面模型 NEAGaN光电阴极 电子亲和势 偶极层 

分 类 号：TN219[电子电信—物理电子学]