TIN OXIDE-BASED GAS SENSORS PREPARED BY THE SOL-GEL PROCESS

Sol-gel process was used to prepare pure and palladium-modified SnO2 t hin films for gas sensors application. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) tec hniques were used to analyse the structure, tile chemical composition and the morphology of the prepared films. Purr tin oxide films have sh own gas-sensing characteristics similar to most of the SnO2 films real ized with other more expensive and more elaborate methods of preparati on, Pd-doped SaO(2) films have shown an improvement in the sensitivity , probably due to the Pd catalytic effect and to the induced microstru ctural changes. (C) 1997 Elsevier Science S.A.