H2S microgas sensor fabricated by thermal oxidation of Cu/Sn double layer

We fabricated a CuO–SnO2 composite thin film for hydrogen sulfide (H2S) gas sensing. The CuO–SnO2 sensing film was prepared by simple process steps. Firstly a metallic Cu/Sn double layer was deposited by thermal evaporation and then the double layer was oxidized in O2 ambient furnace to obtain CuO–SnO2 composite thin film. The sensing properties of the film to H2S gas were measured at the operating temperature of 200 °C. The film showed more than 90% of relative resistance change to H2S gas of 1 ppm at the operating temperature and had a good selectivity to H2S gas.