Fabrication and NOx Sensing Characteristics of $WO_{3}$ Based Thick Film Devices Doped with $TiO_{2}$ and Noble Metals

NOx sensors using tungsten oxide films as a base material were prepared and their electrical and sensing characteristics have been investigated. The thick films doped with or showed higher sensitivity and better sorption characteristics to NOx gas than the pure films material in air at operating temperature of . By addition of noble catalysts, such as Ru or Au, to the thick films, their sensitivity, recovery and selectivity to NOx gas were found to be more enhanced.