Hydrogen sensitive Ga2O3 schottky diode sensor based on SiC

Pt/Ga2O3/SiC metal-reactive insulator-silicon carbide (MRISiC) devices operated as Schottky diodes were characterized for their hydrogen gas sensitivity. The sensors have been tested towards different concentrations of hydrogen gas as a function of operating temperature. This study shows advantages of this structure compared to the pure thin film (90nm) Ga2O3 conductometric sensor. The Ga2O3 thin films were prepared by the sol-gel process and deposited onto the transducers by spin-coating. For both types of sensors, the operating temperature was controlled by a micro heater located beneath the structure. It was found that cycling the ambient from synthetic air (SA) to 1% H-2 in SA air produces repeatable changes of the forward voltage at fixed forward bias. At high temperature (above 500 degreesC), the response time of the sensors decreases. Furthermore, the sensor shows remarkable stability and the decrease in bias voltage subject to 1% H-2 was 210 mV.