Publication Date:
2014-10-10
Description:
Devices based on series-connected Schottky junctions and β-Ga 2 O 3 /SiC heterojunctions characterized as hydrogen sensors Journal of Sensors and Sensor Systems, 3, 231-239, 2014 Author(s): S. Nakagomi, K. Yokoyama, and Y. Kokubun Field-effect hydrogen gas sensor devices were fabricated with the structure of a series connection between Schottky junctions and β-Ga 2 O 3 /6H-SiC heterojunctions. β-Ga 2 O 3 thin films were deposited on n-type and p-type 6H-SiC substrates by gallium evaporation in oxygen plasma. These devices have rectifying properties and were characterized as hydrogen sensors by a Pt electrode. The hydrogen-sensing properties of both devices were measured in the range of 300–500 °C. The Pt/Ga 2 O 3 /n-SiC device revealed hydrogen-sensing properties as conventional Schottky diode-type devices. The forward current of the Pt/Ga 2 O 3 /p-SiC device was significantly increased under exposure to hydrogen. The behaviors of hydrogen sensing of the devices were explained using band diagrams of the Pt/Ga 2 O 3 /SiC structure biased in the forward and reverse directions.
Print ISSN:
2194-8771
Electronic ISSN:
2194-878X
Topics:
Electrical Engineering, Measurement and Control Technology
