High Responsivity Optical GaN Switch

This effort seeks to develop a novel wide bandgap photoconductive semiconductor switch capable of operating at >150 deg C that can hold off 1200–2000 V while supplying 10–120 A for applications in electro-hydrostatic and electro-mechanical actuator motor drives for air platforms. As a follow-on from Phase I efforts, this Phase II project proposes to optimize photoconductive gallium nitride (GaN) devices, in a vertical geometry,  to meet the voltage and current requirements. Photoconductive GaN has demonstrated very high photoresponsivity with sub-gap excitation, allowing high current output with an inexpensive, compact, low-power, 405 nm laser diode. The scope of work includes optimizing GaN material doping and device geometry (substrate, thickness, area, contact geometry) with characterization of continuous and dynamic optical response, in addition to high-temperature behavior, culminating in the demonstration of a prototype small-form-factor optical switching device package. Material growth, device fabrication, and prototype design/build will be completed by the lead, Kyma, and the majority of optical–electrical testing, with supporting simulation efforts will be completed at UMKC (subcontractor).