Effect of thickness on optical properties for (SnO2:3%Cu) thin films prepared by chemical spray pyrolysis technique

Abstract

Thin transparent film of SnO2:3%Cu have been prepared on aborosilicate glass by using chemical spray pyrolysis technique. Absorptance and transmittance spectra have been recorded in the wavelength range (300-900) nm, in order to study the optical constants as Reflectance(R), refractive index (no) ,extinction coefficient(ko) ,real and imaginary parts of the dielectric constant and optical conductivity(σ) .The forbidden energy gap for both direct transitions have been calculated it was found that the energy gap decrease as the film thickness increased, on contrary with Urbach energy which increase as the film thickness increase