Mechanism of oxygen sensing on beta -Ga sub(2)O sub(3) single-crystal sensors for high temperatures

The oxygen-sensing mechanism on gallium oxide sensors has been analyzed in the presence of an oxygen gas flow at elevated temperatures: 700, 750, 800, 850, 900, 950, and 1000 degree C. For the present study, the sensors were prepared based on a beta -Ga sub(2)O sub(3) single crystal in a sandwich structure using three different shapes of the electrodes: quadratic-spot, plate, and mesh type. The results revealed that the oxygen-sensor performances (sensitivity and response/recovery time) of the beta -Ga sub(2)O sub(3) single crystal depended on the operating temperature. A maximum sensitivity of 2.0 was obtained at temperature around 800 degree C, while the shortest response time of about 5s was found at 700 degree C. Moreover, analyzing the oxygen gas-sensing mechanism at various temperatures it can be concluded that at lower temperatures (