Characteristic Of Trigger Photoelectric Threshold For High Gain Semi-Insulating GaAs Photoconductor Switches

Compared with the traditional switch,photoconductive semiconductor switch(PCSS)have many advantages,such as fast switching speed,low timing jitter,small parasitic inductance,capacitance small,and simple structure,especially its high voltage,large power storage capacity made it occupy a great application dominant position in the field of pulsed power and other technologies,PCSS fabricated with III-V semiconductor compounds,such as:GaAs,InP,,due to various phenomena appear in the locked mode,the areas of its application are more open.In this paper,based on the experiments of photoelectric threshold for high gain photoconductive switch,combined with Gunn Effect principle,the photoelectric threshold characteristics related to high gain semi-insulating GaAs PCSS are analyzed theoretically.Specific conclusions are as follows:1 The width of phtoactivated charge domain affected by the carrier concentration and the bias field is simulated on a high gain semi-insulating GaAs photoconductive switch.The simulation results show that:the domain width significantly affected the carrier concentration,but the influence caused by bias electric fields can be neglected,and the size of phtoactivated charge domain under the trigger threshold condition is approximately 1?m magnitude.The simulation results are basically consistent with the experimental results.2 According to the photoelectric threshold experiments of the high gain semi-insulating GaAs PCSS,and the model of phtoactivated avalanche charge domain,the analysis expression of the threshold trigger energy and the threshold bias electric field is obtained,the theoretical derivation is well agreement with the experimental results.