Effect of mixing ratio of (SnO2)1-x(In2O3)x thin film on gas sensitivity

Abstract

In this work, Nitrogen dioxide gas sensor was manufactured from SnO2 and (SnO2)1-x(In2O3)x at different atomic ratios (x=0.05, 0.1 and 0.15) using pulsed laser deposition technique. The effect of the preparation ratio on structural properties, surface topography, optical and electrical characteristics and gas sensor efficiency were studied. The x-ray diffraction measurements showed polycrystalline structures for all samples and their crystallite size decreases with increasing the doping ratio. The AFM measurement illustrates spherical SnO2 shapes converted to filament-like shapes at x=0.1, and that the average particle diameter decreased, while the RMS roughness increased with increasing ratio. The best samples in terms of gas sensitivity were produced at the 0.1 ratio due to the associated with low particle sizes and high charge carrier concentration. The highest gas sensitivity appeared at 200 °C operating temperature, and it is increased with gas concentration as a second-order equation and be nearly stable at 400 ppm NO2 gas. The best sample appeared at 10% In2O3:SnO2atomic ratio.