SnO2 thin film sensor having NiO catalyst for detection of SO2 gas with improved response characteristics

Present work focuses on the growth of SnO2 thin films with high electrical resistivity using RF sputtering technique for fabrication of SO2 gas sensors. NiO catalyst has been incorporated over the surface of SnO2 thin film in the form of continuous layer and dotted nanoclusters to improve the response characteristics. Enhanced sensing response of about 56 has been observed for the NiO dotted cluster/SnO2 sensor at a relatively lower operating temperature of 180 degrees C towards 500 ppm SO2 gas. The contribution of both (i) modulation of depletion region at the interface of n type SnO2 film and p type NiO catalyst on interaction with the target SO2 gas and (ii) the spill over mechanism are considered to be the main reasons for the obtained enhanced response. (C) 2017 Elsevier B.V. All rights reserved.