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

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.