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.