Study of Ga2O3 thin film gas sensors

In this paper we present the gas sensing performance of pure, doped and Pt modified Ga(2)O(3) thin films prepared by the sold-gel process. The oxygen gas sensing performance of the binary compound Ga(2)O(3)-ZnO is compared with that of pure Ga(2)O(3) and ZnO. The Ga(2)O(3)-ZnO binary compound sensor showed preferred gas sensing in the temperature range of 450 to 550 C and outperformed the pure Ga(2)O(3) and ZnO sensors for every oxygen gas concentration tested. Furthermore, the stoichiometry of the semiconducting Ga(2)O(3) has been confirmed by X-ray Photoelectron Spectroscopy (XPS). For H(2) measurements, a 70nm layer of Pt was deposited on top of the Ga(2)O(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(2) response and recovery times by over 65%.