Thermal Evaporation 법에 의해 제조된 WO3 박막과 NiO-WO3 박막의 전기적 특성에 관한 연구

Abstract

WO3 and NiO-WO3 thin films were deposited on a Si (100) substrate by using high vacuum thermal evaporation. The effects of various film thicknesses on the surface morphology WO3 and NiO-WO3 thin films were investigated. X-ray diffraction (XRD), Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were employed to characterize the deposited films. The results suggest that as WO3 thin films became thick, certain size of grain grew. On the other hand, their grain grew up to a certain size(?) NiO-dopint to WO3 thin films inhibited the grain growth five times less than undoped WO3 thin films. doping This results show that NiO dope inhibited the grain growth of WO3 thin films. Also, the variation of doping growing NOx sensitivity(RNOx/Rair) to the thickness of WO3 and NiO-WO3 thin films were measured according to the thickness change of thin films and the working temperature of sensor in 5 ppm NOx gas. As a result, NiO-WO3 thin films showed more excellent properties than WO3 thin films for NOx sensitivity.