红外技术, 2017, 39 (12): 1087, 网络出版: 2018-01-09
一种利用反射率理论模型指导K2CsSb光电阴极的制备方法
Preparation Method of K2CsSb Photocathode Using the Reflectance Theory Model
摘要
针对中微子和宇宙射线探测用的大尺寸K2CsSb 光电阴极,本文首先利用光学导纳矩阵法,推导了适用于多层膜的K2CsSb 光电阴极理论模型。通过该模型对K2CsSb 光电阴极生长提出了增透层蒸镀、底K 蒸镀、K/Sb 同蒸、进Cs 蒸镀4 个阶段的制备方法,在对各个阶段的反射率变化进行的理论仿真后,发现K2CsSb 厚度远低于KSb 厚度,整个阴极结构应该为K2CsSb/K3Sb/增透层/玻璃的4 层结构;仿真计算结果表明,利用该制备方法获得的K2CsSb 光电阴极厚度约为40 nm。实验中,由于K 与Sb 同时蒸镀时采用了不同的蒸镀比例会导致截然不同的反射率曲线走势,从而影响到K2CsSb 的量子效率差异。
Abstract
To investigate the K2CsSb photocathode used for neutrinosor cosmic ray detection, a theoretical model of K2CsSb photocathode for multi-layer films was deduced from the optical admittance matrix method in this paper. Using this model, the four-stage preparation method for the growth of K2CsSb photocathode had been proposed, which consists of the evaporation of the transmission enhanced layer (TEL), the basic K evaporation, K/Sb co-evaporation, and Cs evaporation. From the theoretical simulation of the changes in reflectivity at each stage, we found that the thickness of K2CsSb is much less than that of K3Sb, and the entire structure should be a four-layer configuration: K2CsSb/K3Sb/TEL/glass, and the total thickness of the K2CsSb photocathode is approximately 40 nm from simulations. The experimental results show that the difference in the reflectance curves caused by the difference in the evaporation ratios between K and Sb lead to a difference in quantum efficiency.
孙建宁, 司曙光, 王兴超, 金睦淳, 李冬, 任玲, 侯巍, 赵敏, 顾莹, 乔芳建, 张昊达, 曹宜起. 一种利用反射率理论模型指导K2CsSb光电阴极的制备方法[J]. 红外技术, 2017, 39(12): 1087. SUN Jianning, SI Shuguang, WANG Xingchao, JIN Muchun, LI Dong, REN Ling, HOU Wei, ZHAO Min, GU Ying, QIAO Fangjian, ZHANG Haoda, CAO Yiqi. Preparation Method of K2CsSb Photocathode Using the Reflectance Theory Model[J]. Infrared Technology, 2017, 39(12): 1087.