Hydrogen gas sensor with self temperature compensation based on β-Ga2O3 thin film

Field-effect hydrogen gas sensor devices with self-temperature compensation based on beta-Ga2O3 thin films were fabricated. A beta-Ga2O3 thin film was deposited on a sapphire substrate by gallium evaporation in oxygen plasma. The resistance between two ohmic electrodes on a beta-Ga2O3 thin film with a Pt gate was decreased in H-2 atmosphere. The sensor could detect 100 ppm H-2 in 20% O-2/N-2 at 400 degrees C. The resistance of the device without the Pt gate electrode did not change significantly with variation in the atmospheric composition. A sensor device with self temperature compensation was constructed by the in-series connection of devices with and without gate electrodes. The output of the sensor device remained stable, even for temperature fluctuations over 100 degrees C in the region of approximately 400-550 degrees C. (C) 2013 Elsevier B. V. All rights reserved.