Fast Switching of 4H-SiC Light Triggered Thyristor by Photoconductive Assistance

Abstract

A 4H-SiC light-triggered thyristor is fabricated and triggered by a 355nm UV laser for fast switching performance by photoconductive assistance. The switching characteristics of the thyristor are tested in a resistive load circuit with a 220nF capacitor as an energy storage element. By combining the high-power UV light with a multi-gate structure, the thyristor is switched on fast through the photoconduction mechanism, overcoming the limitation of the internal positive feedback formation process. The peak current of the thyristor reaches to 328A, and the corresponding current density is about 8.2kA/cm2. The highest current rising rate (dI/dt) obtained in this work is 27.3kA/ $\mu $ s, and the corresponding current density rising rate is 682.5 kA/(cm $^{{2}}\cdot \mu $ s).