超二代像增强器多碱阴极Cs-Sb激活机理研究  

Cs-Sb Activation Mechanisms of Multi-Alkali Cathode of Super Second Generation Image Intensifier

作　　者：李晓峰[1,2] 赵学峰[2] 郭骞[2] 张云昆[2] 

机构地区：[1]微光夜视技术重点实验室,西安710065 [2]北方夜视技术股份有限公司,昆明650114

出　　处：《真空科学与技术学报》2013年第9期903-908,共6页Chinese Journal of Vacuum Science and Technology

基　　金：微光夜视技术重点实验室基金项目(J2011016)

摘　　要：介绍了在同一阴极玻璃窗上制作超二代像增强器Na2KSb(Cs)膜层和Na2KSb(Cs-Sb)膜层的方法。测量了超二代像增强器Na2KSb(Cs)膜层和Na2KSb(Cs-Sb)膜层的光谱响应,结果表明Na2KSb(Cs)阴极膜层和Na2KSb(Cs-Sb)膜层光谱响应的长波阈值均为915 nm,逸出功为1.35 eV。尽管其长波阈值和逸出功相同,但Na2KSb(Cs-Sb)膜层的光谱响应较Na2KSb(Cs)阴极膜层的高,说明Cs的作用主要是降低电子亲和势,而Cs-Sb的作用除同样具有降低电子亲和势的因素外,还有增加光谱响应的作用。为了比较Na2KSb(Cs)膜层和Na2KSb(Cs-Sb)膜层的结构变化,测量了Na2KSb(Cs)膜层和Na2KSb(Cs-Sb)膜层的荧光谱,结果表明两者相比,Na2KSb(Cs-Sb)阴极膜层不仅荧光的峰值强度更高,而且荧光的峰值波长也更短,这表明Na2KSb(Cs-Sb)阴极膜层较Na2KSb(Cs)膜层具有更多的跃迁电子,同时跃迁电子的能级更高,从而导致光谱响应更高。因此Na2KSb阴极膜层在表面Cs-Sb激活之后,光谱响应增加的原因除有表面逸出功降低的因素之外,还有Na2KSb膜层内部能带结构发生变化的因素。Na2KSb阴极膜层在进行Cs-Sb激活之后,其表面存在一层Cs-Sb膜层,而这两种膜层之间又存在应力,从而导致Na2KSb膜层的晶格发生畸变,致使能带结构发生变化。The spectral response of the Na2KSb （Cs） and Na2KSb （Cs-Sb） films, deposited by vacuum evaporation, respectively, on different sectors of glass window of the multi-alkali cathode of the second generation image intensifier, were evaluated. The work functions and the long wave threshold of the Na2KSb（Cs） and Na2KSh（Cs-Sb）films were found to be 1.35 eV and 915 nm, respectively. The results show that the Cs and Cs-Sb activation mainly reduced the electron aflqnity, but the Cs-Sb activation generated a higher spectral response. The slightly blue-shifted fluorescence peak of the Cs-Sb activated Na2KSb is higher than that of the Cs-aetivated Na2KSb, possibly because the transition involves more electrons and higher energy levels. Moreover, the Cs-Sb activation of Na2KSb not only reduced the work function, but also deformed the surface energy band because of the stress-induced lattice distortion at the interface of the Cs-Sb layer and Na2KSb films.

关 键 词：多碱阴极 光致荧光 光电发射 电子跃迁 光谱响应 

分 类 号：O462.3[理学—电子物理学]