Preparation of WO₃ Nanorods by Glancing Angle DC Reactive Magnetron Sputtering Deposition for NO₂ Gas Sensing Application

Abstract

In this study, we present a tungsten trioxide (WO3) nanorods based gas sensor for NO2sensing at operating temperature range 150-350 °C in purify dry air carrier. WO3nanorods were fabricated by dc reactive magnetron sputtering with glancing angle deposition (GLAD) technique on silicon (100) wafer and alumina substrates interdigitated with gold electrode. The length of WO3nanorods was varied from 370 nm to 620 nm. As-deposited nanorods were annealed at a temperature of 400 °C in air for 1 h. The microstructure and phase structure of WO3nanorod were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. XRD of annealed WO3nanorod showed polycrystalline phase. The WO3nanorods length 420 nm exhibit excellent NO2sensing properties with a maximum sensitivity of 360 at 250 °C operating temperature with fast response and recovery time.