Influence of electric field penetration on uniformly doping GaAs photocathode photoelectric emission properties

Abstract

In order to explore the changes of photoelectric emission properties of GaAs material employed in the third generation low light level (LLL) image intensifiers, the influence of electric field penetration on photoelectric emission properties of uniformly doping GaAs photocathode is studied. Based on the establishment of electric field penetration model for uniformly doping GaAs photocathode, the photoelectric trajectories in GaAs photocathode have been calculated in different penetration voltages. The results show that electric field penetration is helpful for enhancing the movement of photoelectrons excitated by the long-wave radiation toward the band bending region (BBR). With increase of electric field penetration, the diffuse circle of photoelectrons reaching the BBR has no obvious difference, and the resolution of GaAs photocathode is improved. The fitted curves of the location distribution of photoelectrons can be expressed by Gaussian formula. The research will be beneficial to promote the development of the LLL night vision technology.