Characterisation of nanostructured SnO2 thin films synthesised by magnetron sputtering and application in a carbon monoxide gas sensor

Tin oxide (SnO2) thin films were deposited onto glass substrates using DC magnetron sputtering system as a CO gas sensor. The dependence of the deposition time on structural, morphological and CO gas sensing properties of SnO2 thin films were investigated. The synthesised SnO2 thin films were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and surface profiler. Also the CO gas sensing properties of SnO2-deposited thin films were performed against a wide range of concentration of CO gas. XRD analysis demonstrated that the degree of crystallinity of the deposited SnO2 thin films strongly depended on the deposition time. Also, SEM and AFM analyses revealed that the size of nanoparticles/agglomerates, and both average and rms surface roughness were enhance with increasing the deposition time. Gas sensors based on these SnO2 nanolayers showed an acceptable response to CO at various concentrations. Also it has been demonstrated that SnO2 sensors are highly suitable for sensing CO gas at comparatively lower operating temperatures.