In this paper, the matrix difference method is used to calculate the photoelectron continuity equation and the outgoing electron flux density equation. The effects of the GaAsP/AlGaAsP recombination rate, electron diffusion coefficient, and activation layer thickness on the time-resolved characteristics and quantum efficiency of a GaAsP photocathode are systematically studied, and the accuracy of the theoretical calculation is verified by experiments. The response speed and quantum efficiency of the GaAsP photocathode can be greatly improved by adjusting the thickness of the GaAsP activation layer reasonably.

Due to the excellent quantum conversion and spectral response characteristics of the AlGaN photocathode, it has become the most promising III-V group semiconductor photocathode in solar-blind signal photoconversion devices in the ultraviolet band. Herein, the influence factors of the time-resolved characteristics of the AlGaN photocathode are researched by solving the photoelectron continuity equation and photoelectron flow density equation, such as the AlN/AlGaN interface recombination rate, AlGaN electron diffusion coefficient, and AlGaN activation layer thickness. The results show that the response time of the AlGaN photocathode decreases gradually with the increase in AlGaN photoelectron diffusion coefficient and AlN/AlGaN interface recombination rate, but the response time of the AlGaN photocathode gradually becomes saturated with the further increase in AlN/AlGaN interface recombination rate. When the thickness of the AlGaN photocathode is reduced from 250 nm to 50 nm, the response time of the AlGaN photocathode decreases from 63.28 ps to 9.91 ps, and the response time of AlGaN photocathode greatly improves. This study provides theoretical guidance for the development of a fast response UV detector.