Evolution of lattice temperature in GaAs photoconductive semiconductor switch employing extrinsic photoconductivity

The evolution of lattice temperature inside an opposed-contact gallium arsenide photoconductive semiconductor switch (PCSS) employing extrinsic photoconductivity is investigated, based on a temperature-dependent "two-channel" model. It is found that a drastic increase in lattice temperature always occurs once the nonlinear switching is developing in the filamentary channel during the conduction process. The maximum rising rate of lattice temperature always occurs after the filamentary channel has switched on, which is determined by the evolution rate of avalanche domains, and the largest increment of lattice temperature is caused at the voltage-locking stage, which is mainly attributed to the existence of static domains near the contacts. Furthermore, it is demonstrated that the evolution trend of lattice temperature can be significantly regulated by the interaction between the filamentary channel and the part outside the filamentary channel in the current channel. On this basis, the effect of an increased illuminating region on preventing PCSS damage is studied, confirming the simulated results and analyses on temperature evolution experimentally.