【Device Papers】Investigation on Avalanche and Optoelectronic Response in Ga₂O₃ Photoconductive Semiconductor Switches

      Researchers from the National University of Singapore have published a dissertation titled "Investigation on Avalanche and Optoelectronic Response in Ga₂O₃ Photoconductive Semiconductor Switches" in IEEE Transactions on Plasma Science.

Abstract

      Photoconductive semiconductor switches (PCSSs) are noted for the rapid turn-on time and optically isolated triggering, making them suitable for high-power applications. Gallium oxide (Ga₂O₃), as an ultra-wide bandgap semiconductor, is promising for use in PCSSs with ultrahigh breakdown voltage and power density. This study investigates the avalanche process of Ga₂O₃ PCSSs triggered by pulsed optical sources through computational simulations, focusing on the electric field distribution, carrier dynamics, and optoelectronic response. The responsivity of Ga₂O₃ PCSS exceeds 100 mA/W when the optical power ranges from 10⁴ to 10⁶ W/cm². The rise time of the switch significantly decreases from 6.5 to 2 ns with an electric field of 6 MV/cm. Results reveal that a high-density avalanche domain forms and propagates within the device with peak electric fields ranging from 6 to 8 MV/cm. Furthermore, we demonstrate that the switching time of Ga₂O₃ PCSS can be shorter than 500 ps. This research provides design guidance and crucial insights into the carrier dynamics of an ultrafast Ga₂O₃ PCSS.

DOI：

https://doi.org/10.1109/TPS.2025.3572181