K2SbCs光电阴极光谱响应特性模拟

摘要

为了探索高性能K2SbCs光电阴极的特征结构,对光电阴极量子效率公式进行了推导,并利用推导出的公式对 K2SbCs 光电阴极量子效率(≈30%)曲线进行拟合,得到拟合相对误差较小结构参数.另外,根据拟合结果分析了对光谱响应造成影响的因素,包括阴极厚度、光电逸出深度、阴极结构参量、光谱响应截止波长等.探索了该光电阴极结构参数范围,据此分析并设计高性能透射式K2CsSb光电阴极.%We report a theoretical investigation of the characteristics of high-performance K2SbCs photocathode. First, we derived a modified formula for the photocathode quantum efficiency. The quantum efficiency (≈30%) curve of the K2SbCs photocathode was then fitted using the modified formula, and the structural parameters were extracted with in reasonable error limits. Next, the fitting results were used to analyze the factors affecting the spectral response, such as the cathode thickness, escape depth of the excited photoelectrons, structure parameters of the cathode, and cut-off wavelength of the spectral response. Finally, the range of parameters affecting the photocathode structure was explored. Our study will be helpful in designing high-performance transmission-mode K2CsSb photocathodes.