Gas sensing performance of Tungsten doped V2O5 nanorod thin-films deposited by hot filament CVD combined with DC sputtering

Abstract

High-quality polycrystalline tungsten doped vanadium pentoxide thin-films were prepared using Hot Filament Chemical Vapor Deposition technique (HFCVD) combined with sputtering by changing target to substrate distance and reaction duration. Scanning electron microscopy and X-ray diffraction revealed that the morphologies and crystalline structures of the films are depending on the deposition parameters such as target to substrate distance and deposition time. Raman spectroscopy is also used to analyse the oxidation states of the vanadium-based films. The deposited nanorod thin-film was exposed to ammonia and ethanol gases to test their gas sensing performance. It exhibits a sensing response of 1.8 and 1.65 at a concentration of 200 ppm ammonia and ethanol and has a recovery time of 44 and 31 s, respectively.