短波响应增强的透射式GaAs光电阴极光电发射性能研究

Study of Photoemission Performance of Short-wave Response Enhanced Transmission-mode GaAs Photocathode

基于量子效率仿真研究,设计并通过分子束外延生长了透射式GaAs光电阴极材料,制作了透射式GaAs光电阴极组件,并对其反射率和透射率进行了测试分析。在超高真空装置中制备了透射式GaAs光电阴极,并实现了整管封接,得到了GaAs光电阴极量子效率曲线。结果表明,通过提高窗口层Al组分并降低发射层厚度可有效增强透射式GaAs光电阴极的短波响应,与标准三代GaAs光电阴极相比,其蓝绿光波段的探测能力得到了有效提升。

Based on quantum efficiency simulation, the transmission-mode GaAs photocath- odes were designed and grown by molecular beam epitaxy （MBE）. The transmission-mode GaAs photocathode modules were manufactured, and the reflectivity and transmissivity of the photo- cathode modules were measured and analyzed. The transmission-mode GaAs photocathodes were prepared and the vacuum devices were sealed in an ultra-high vacuum equipment, and the quantum efficiency curves were obtained. The results show that the short-wave response of transmis- sion-mode GaAs photocathode could be enhanced by increasing A1 composition in window layer and reducing the thickness of emission layer. In comparison with the standard third-generation GaAs photocathode, the short-wave response enhanced GaAs photoeathode has stronger detection capability to blue-green light.