Study On High Power GaAs Photoconductive Semiconductor Switches In Time Domain

A Photoconductive Semiconductor Switch (PCSS) is a new kind of devices that are composed of photoconductive semiconductor and the ultra fast pulse laser. It has advantages in response speed, jitter free triggering, high voltage-resistant. The discovery of nonlinear mode under high electric field of III-IV semiconductor makes it possible for the applied system of PCSS's to be more small, practical and integrative, therefore they are paid much more attention to.In this thesis, the inherent characteristics of PCSS material are investigated. The reasons of response speed, jitter free triggering, high voltage-resistant are explained. And the compensation characteristics of N-type GaAs with deep level impurity Cu are discussed. A physical model based on drift- diffusion theory is established. Many particular phenomenon of high power devices under high field are considered in this model. The time-domain finite-difference method is developed to simulate the characteristics of steady-state and transient-state. By comparing the profile of field before the trigger with that after the trigger, the physical essence of the nonlinear operational mode in PCSS's is stated.