Investigating the Performance of a Lateral 4H-SiC Photoconductive Switch With a Sinking-Electrode Structure

A lateral PCSS with a sinking-electrode structure was proposed in this work. Silvaco TCAD was used to simulate the electric field distribution of the switches with different groove etching depths. The simulation results show that the internal peak electric field and external quantum efficiency (EQE) of a sinking-electrode PCSS with a 1 mm gap were 61% and 270% of the conventional switch, respectively. A 355 nm YAG laser with a dc high voltage source was also used to test the sinking-electrode switches with different electrode gaps. The sinking-electrode switch with a small electrode gap achieved the same breakdown voltage value with higher current and quantum efficiency compared to the conventional switch with a large gap. The acquired experimental results were in good agreement with the simulated outcomes, and the good ON-state performance confirmed the improved photoelectric conversion efficiency and high voltage resistance of the introduced sinking-electrode PCSSs.