Indium tin oxide (ITO) thin film gas sensor for detection of methanol at room temperature

Thin films of indium tin oxide (In2O3 + SnO2) (ITO) were grown on alumina substrate using the direct evaporation method. The sensing characteristics of these films to methanol vapors were studied at room temperature. The effects of different concentrations of tin oxide in indium oxide and film thickness on sensitivity were studied. The effects of thin layers of noble metals-Au, Ag, Pt and Cut on top of ITO films were studied. A novel approach of stimulated recrystallization of ITO film by depositing ITO film over ultra thin layer of Cu stimulator was used to improve the sensitivity, selectivity and minimum detection limit of methanol sensors operating at room temperature. (C) 2003 Elsevier B.V. All rights reserved.