Spin coated tin oxide: a highly sensitive hydrocarbon sensor

The present investigation deals with the electrical response of ruthenium incorporated tin oxide thin film deposited by spin coating method, as a mean to improve the selectivity and sensitivity towards hydrocarbon gas. The thin film with ruthenium in tin oxide matrix exhibits remarkable sensitivity (s=672) and selectivity towards hydrocarbon gas (Liquid petroleum gas) at the operating temperature of 300 °C. The X-ray diffraction (XRD) analysis of ruthenium incorporated tin oxide, fired at 400 °C reveals the polycrystalline nature, while pure tin oxide does not show crystalline nature at such a low firing temperature. A systematic evaluation of the surface coverage and morphology using techniques like energy dispersive X-ray analysis, scanning electron microscopy and XRD reveals a crucial role of the ruthenium species in the enhancement of sensitivity, selectivity and morphology. The correlation between ruthenium incorporation and the improvement in the sensitivity and selectivity towards hydrocarbon is discussed.