Hydrogen sensitive GA 2O 3 Schottky diode sensor based on SiC

• Published in: Sensors and actuators. B, Chemical Vol. 100; no. 1; pp. 94 - 98
• Main Authors: Trinchi, A., Wlodarski, W., Li, Y.X.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2004
• Subjects: Gallium oxide; Gas sensor; Hydrogen; Schottky diode; Hydrogen; Gallium oxide; Gas sensor; Schottky diode
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2003.12.028

Pt/Ga 2O 3/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 (90 nm) Ga 2O 3 conductometric sensor. The Ga 2O 3 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 °C), 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.