Performance of a Novel Rear-Triggered 4H-SiC Photoconductive Semiconductor Switch

Radial lateral structure photoconductive switches are fabricated in this work via vanadium-doped 4H-SiC and high-purity 4H-SiC materials. The switches are triggered by 355-and 532-nm laser, and the performance of the switch is compared in the applied voltage range of 1-10 kV and laser energy range of 0.3-14 mJ. The experimental results show that the conduction current of the laser incident from the rear is larger. Simulations of the current density distribution of a 2-D cross section of the photoconductive switch provide theoretical support for this phenomenon. Additionally, the conduction current of the high-purity material is found to be higher than that of the vanadium-doped material under the same conditions.