Optically Activated 4H-SiC p-i-n Diodes for High-Power Applications

TLDR

This initial work forms the basis for the further development of high‑power high‑speed SiC bistable switches. The authors present optically activated SiC p‑i‑n diodes to harness SiC power electronics and optically controlled device technology for high‑temperature and high‑power applications. The diode’s response time is mainly limited by the RC time constant from the junction capacitance and the current‑limiting resistor in the test circuit. Fabricated on an n‑type 4H‑SiC substrate, the diodes switch on with a single 337.1 nm UV laser pulse of 1.2 mJ at 1000 V reverse bias, exhibiting a 180 ns FWHM, rise time under 10 ns, and fall time around 200 ns.

Abstract

To realize the benefits of SiC power electronics and optically controlled device technology, we present in this letter optically activated SiC p-i-n diodes for high-temperature and high-power applications. The diodes were fabricated on an n-type 4H-SiC substrate, and measurements show that, when tested at a reverse bias of 1000 V, the diode was switched on by a single UV (337.1 nm) laser pulse with 1.2-mJ optical energy. The FWHM is about 180 ns with a rise time of less than 10 ns and a fall time of about 200 ns. The response time is primarily limited by the RC time constant from the junction capacitance of the diode and the current-limiting resistor in the test circuit. This initial work forms the basis for the further development of high-power high-speed SiC bistable switches.