Pd-WO3박막을 이용한 수소센서의 연구

Abstract

Physicochemical and electrical properties for hydrogen gas sensors based on Pd-deposited WO3 thin films were investigated as a function of Pd thickness, annealing temperature, and operating temperature. WO3 thin films were deposited on an insulating material by thermal evaporator. XRD, FE-SEM, AFM, and XPS were used to evaluate the crystal structure, microstructure, surface roughness, and chemical property, respectively. The deposited films were grown WO3 polycrystalline with rhombohedral structure after annealing at 500℃. The addition effect of Pd is not the crystallinity but the suppression of grain growth of WO3. Pd was scattered an isolated small spherical grain on WO3 thin film after annealing at 500℃ and it was agglomerated as an irregular large grain or diffused into WO3 after annealing at 600℃. 2 nm Pd-deposited WO3 thin films operated at 250℃ showed good response and recovery property.