Gas-sensing characteristics of undoped-SnO2 thin films and Ag/SnO2 and SnO2/Ag structures in a propane atmosphere

The gas-sensitivity properties of SnO2 thin films as well as Ag/SnO2 and SnO2/Ag structures in an atmosphere containing propane (CA) were examined. The SnO2 and Ag films were deposited by a spray pyrolysis technique and vacuum evaporation, respectively. Soda-lime glass was used as the substrate for all the structures in this study. The sensors were measured in a propane atmosphere with different gas concentrations (50, 100, 200, 300, 400, and 500 ppm) at different operation temperatures (22, 100, 200, and 300 degrees C). The Ag/SnO2 structure, sintered a 400 degrees C for 1 h, showed the highest sensitivity, of the order of 400 at an operation temperature of 200 degrees C. The results show that the addition of Ag in the tin oxide films effectively acts as a catalyst in propane sensors and confirm the potential feasibility of using Ag as a catalyst in SnO2-based propane sensors. (C) 2006 Elsevier Inc. All rights reserved.