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

In the present work systematic studies on optical properties of six SnO2 thin films of varying thickness have been done which are correlated for a deeper understanding of gas sensing phenomenon. The lowest value of refractive index and packing density for 90 nm SnO2 film substantiate the presence of voids and defects in the film. Further, dispersion in refractive index of SnO2 thin films was analyzed in the light of single oscillator model (SOM). A good agreement between the experimental refractive index data with single oscillator model was observed. The value of Eo, Ed and So is found to be the lowest for 90 nm thin SnO2 film which further confirms the presence of large concentration of voids and lower density. The outcome of the present study proposes the potential use of 90 nm thin SnO2 film as the base material which can be used for efficient detection of LPG gas.