Transverse U-shaped GaN light-triggered thyristor achieving enhanced optical absorption and high-speed switching

Abstract This work presents a U-shaped GaN light-triggered thyristor (LTT) with a transverse architecture designed to maximize optical absorption in the active base region for high-speed, high-voltage switching. Positioning the p-base at the illuminated bottom surface enables direct 350 nm excitation, minimizing optical losses and achieving over 97% photon absorption in the p-base, thereby enhancing photocarrier generation. Numerical simulations incorporating optical modeling confirm robust forward-blocking operation at 460 V and rapid optical switching; the anode-to-cathode voltage drops from 460 V to 5.2 V, and the anode current increases to 7.6 A cm −2 under 0.1 W cm −2 illumination. The intensity-dependent simulations show that the turn-on time is 311 ns at 0.1 W cm −2 and decreases to 99 ns at 1.0 W cm −2 , whereas d i /d t increases from 61.1 to 76.6 A cm −2 µ s with higher light intensity. Fast turn-off is also observed, consistent with GaN’s short minority-carrier lifetime. These results demonstrate that the proposed U-shaped GaN LTT enables efficient optical triggering and rapid switching with high-voltage capability, making it a promising solid-state switch for compact pulse-power applications.