SnO2/Au multilayer heterostructure for efficient CO sensing

Abstract In this work, SnO2/Au multilayered heterostructures based gas sensors are fabricated to detect CO gas. The Sn/Au multilayer structure was grown by thermal evaporation method followed by oxidation at elevated temperature. The structural characterization of the grown structures was performed by X-ray diffraction (XRD) and the oxidation analysis was performed by X-ray photoelectron spectroscopy (XPS). The electrical properties of SnO2/Au multilayered heterostructures were studied in the temperature range from 25 °C to 300 °C and sensing of gas was performed for CO (100ppm). A significant enhancement in CO sensing at 300 °C was observed in SnO2/Au multilayered heterostructures than pristine SnO2. The pristine SnO2 sensor displays a sensitivity of 30.81% while it increased to 67.46% in case of SnO2/Au multilayered heterostructures. The change in the sensitivity could be correlated with the oxygen deficiencies as observed in photoluminescence spectra.