Low temperature HFCVD synthesis of tungsten oxide thin film for high response hydrogen gas sensor application

A quick and efficient approach was employed for the growth of nanocrystalline tungsten oxide (WO3) thin films using one-step hot filament chemical vapor deposition (HFCVD) method at low temperature. In a typical experiment, the parent material tungsten (W) was subjected to oxidation, gasification and its subsequent condensation to obtain the uniform deposition of WO3 thin film on silicon substrate at significantly low temperature of similar to 200 degrees C. Prepared WO3 thin film possessed the cauliflower nanostructure (WCNs) with typical monoclinic WO3 crystal structure. Prepared WCNs thin films were applied for the detection of hydrogen (H-2) gas at 100 ppm. H-2 response increased with rise in temperature and the maximum response of similar to 87% was obtained at the optimized temperature of similar to 250 degrees C with response time 180 s. (C) 2019 Elsevier B.V. All rights reserved.