超快光电导开关瞬态电阻计算方法

Ultra-Fast Photoconductive Switches' Transient Resistance Calculation Method

应用电磁学原理,研究了光电导开关输出电流中的位移电流和传导电流,认为位移电流可以由内建电场变化和负载分压过程引起。内建电场变化引起的位移电流在大间隙光电导开关中可以忽略;负载分压引起的位移电流能够抑制光电导开关输出电流的变化。横向光电导开关的输出电流主要依赖电极吸收载流子形成的传导电流和负载分压引起的位移电流。建立了基于载流子输运过程与瞬态电磁过程的全电流模型。根据此模型得到了光电导开关瞬态电阻计算方法,与电导率模型相比,该方法可以更精确描述超快光电导开关的瞬态电阻。

By electromagnetic theory, the induced current and the conduction current in the output current of photoconductive switches（PCSS） been studied. It is found that the displacement current can created by the moving built-in field and the electric voltage shifting from the PCSS to the load. We consider that the displacement current can created by the moving built-in field current in the large gap PCSS can be neglected, and the output current of large gap PCSS＇ s relies largely on the conduction current formed by the absorption of photo-production carriers and the displacement current created by the electric voltage shifting from the PCSS to the load. A total current mode is built based on the transportation of the photogenerated carriers and the transient electromagnetism process. In contrast with conductivity mode, the transient resistance of PCSS is described accurately by the new mode.