Theoretical Revision and Experimental Comparison of Quantum Yield for Transmission-Mode GaAlAs/GaAs Photocathodes

The quantum yield formula for uniform-doping GaAlAs/GaAs transmission-mode photocathodes is revised by taking into account the light absorption in the window layer. By using the revised quantum yield formula, the domestic and ITT's experimental quantum yield curves are fitted and the fitted curves match well with the experimental curves. In addition, the fit results show that the integral sensitivity and quantum yield of domestic image intensifier tube has achieved 2130μA/lm and 45%, nearly reaching ITT's third generation level in 2002, whereas the discrepancy in cathode performance is mainly embodied in the electron diffusion length and back interface recombination velocity.