Uniform Current Density and Thermal Distribution in Vanadium-Doped 4H-SiC PCSS Based on Dual-Beam Synchronous Excitation

The mitigation of current crowding and the improvement of thermal distribution uniformity are of great significance for the high-power applications of silicon carbide photoconductive semiconductor switches (SiC PCSSs). The transient output characteristics of a vanadium-doped 4H-SiC PCSS with a vertical electrode structure were investigated by changing the optical path of the 532 nm pulse laser beam. Furthermore, a multiphysics-coupled model was established to simulate the distribution of current density and heat generation within the PCSS during conduction. The results indicate that dual-pulse laser beam (dual-beam) synchronous excitation significantly reduces the peak current density and temperature at the electrode-semiconductor-insulator triple point, promotes a more uniform distribution of these parameters within the substrate, and does so without compromising the transient output characteristics of the PCSS.