Effect of Thickness on Optical Dispersion of SnO2 Thin Films


Highly conducting and transparent SnO2 thin films have been prepared by a simple and low-cost spray pyrolysis technique on glass substrates. The optical properties and dispersion parameters of tin oxide have been studied as a function of film thickness. The changes in dispersion parameters and Urbach tails were investigated. The optical energy gap Eg decreased with increasing film thicknesses from 200 to 350nm ,and this can be attributed to the increase in the density of localized states and cause an expanding in the Urbach tail and consequently decrease the energy gap from 3.60 eV to 3.49 eV. The single-oscillator parameter has been reported.