The effect of dopants on the sensing selectivity of SnO/sub 2/ thin films-based gas sensors

The development of metal oxide gas sensor devices with optimized selectivity and sensitivity has been gaining prominence in recent years. This paper reports the influence of doping to optimize the selectivity of the SnO/sub 2/ thin films doped with Pt, Pd, CuO, ZnO and TiO/sub 2/ toward the variety of vapor gases such as cyclohexane, chloroform, benzene and acetone. The films were prepared by using electron beam evaporation. The sensing selectivity was based on the electrical change of the films when being exposed to vapor gases. Each film shows a different response toward different vapor gases. The selectivity of these films was observed to be depended markedly on the doping materials.