Stability of SnO2/Fe2O3 multilayer thin film gas sensor

SnO2/Fe2O3 multilayer thin film was prepared by sol-gel technique and analyzed by scanning electron microscopy (SEM), transmission electron miscroscopy (TEM), and atomic emission spectroscopy (AES), The gas-sensitive characteristics of the SnO2/Fe2O3 mull ilayer thin film was investigated. The SnO2/Fe2O3 thin film exhibited improved selectivity and stability, but slightly reduced sensitivity, compared with SnO2 and Fe2O3 thin films. The existence of an interfacial transition layer between the SnO2 layer and the Fe2O3 layer and the stabilization mechanism of the SnO2/Fe2O3 multilayer thin film are discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.