Study of Ga/sub 2/O/sub 3/ thin film gas sensors

In this paper we present the gas sensing performance of pure, doped and Pt modified Ga/sub 2/O/sub 3/ thin films prepared by the sold-gel process. The oxygen gas sensing performance of the binary compound Ga/sub 2/O/sub 3/ is compared with that of pure Ga/sub 2/O/sub 3/ and ZnO. The Ga/sub 2/O/sub 3/-ZnO binary compound sensor showed preferred gas sensing in the temperature range of 450 to 550/spl deg/C and outperformed the pure Ga/sub 2/O/sub 3/ and ZnO sensors for every oxygen gas concentration tested. Furthermore, the stoichiometry of the semiconducting Ga/sub 2/O/sub 3/ has been confirmed by X-ray photoelectron spectroscopy (XPS). For H/sub 2/ measurements, a 70nm layer of Pt was deposited on top of the Ga/sub 2/O/sub 3/ to enhance the response and a comparison of the device with and without this layer is also presented. It was found that the addition of the Pt layer decreased the H/sub 2/ response and recovery times by over 65%.