NO 2 Sensing Properties of WO 3 Thin Films Deposited by Rf-Magnetron Sputtering

Abstract

Tungsten trioxide (WO 3 ) thin films were deposited by Rf-magnetron sputtering onto Pt interdigital electrodes fabricated on corning glass substrates. NO 2 gas sensing properties of the prepared WO 3 thin films were investigated by incorporation of catalysts (Sn, Zn, and Pt) in the form of nanoclusters. The structural and optical properties of the deposited WO 3 thin films have been studied by X-ray diffraction (XRD) and UV-Visible spectroscopy, respectively. The gas sensing characteristics of all the prepared sensor structures were studied towards 5 ppm of NO 2 gas. The maximum sensing response of about 238 was observed for WO 3 film having Sn catalyst at a comparatively lower operating temperature of 200°C. The possible sensing mechanism has been highlighted to support the obtained results.