Study of optical properties of SnO2 thin films and their influence on gas-sensing response

In the present work, systematic studies on the optical properties of six tin (IV) oxide (SnO2) thin films of varying thicknesses were done and their influence on gas sensing response were studied. Refractive index and packing density of 90nm tin (IV) oxide film was observed to be lowest among all six films which the presence of voids and defects in the film. Further, the dispersion in the refractive index of tin (IV) oxide thin films was analyzed in light of the single-oscillator model (SOM). A good agreement between the experimental refractive index data and the SOM was observed. The values of E-o, E-d and S-o were found to be the lowest for the 90nm thin tin (IV) oxide film, which further confirms the presence of a large concentration of voids and a lower density. The outcome of the present study suggests the potential use of 90nm thin tin (IV) oxide film as the base material that can be used for efficient detection of liquefied petroleum gas.