H2S sensing properties of the SnO2-based thin films

The SnO2-based thin films of SnO2–Ag2O, SnO2–Ag and SnO2–CuO were prepared by magnetron sputtering on the silicon substrates with Si3N4 surface layer and Pt interdigitating electrodes. The sensitive properties of these films to H2S were measured in the temperature range of 100–450°C. The results indicate that all the films exhibit high sensitivity to H2S, and the SnO2–Ag2O film shows the best performance in the response and recovery on exposure to 1 ppm H2S. The better recovery can be obtained only at high temperature, and the sensitivity of the SnO2–Ag2O film is the highest among those of the films at high temperature. In addition, the thickness of the Ag2O doping layer has little effect on the sensitivity of the SnO2–Ag2O film.