Determination and analysis of dispersive optical constant of TiO2 and Ti2O3 thin films

Electron beam evaporation technique was used to prepare TiO2 and Ti2O3 thin films onto glass substrates of thicknesses 50, 500 and 1000 nm for each sample. The structural investigations revealed that the as-deposited films are amorphous in nature. Transmittance measurements in the wavelength range (350-2000 nm) were used to calculate the refractive index n and the absorption index k using Swanepoel's method. The optical constants such as optical band gap Egopt, optical conductivity σopt, complex dielectric constant, relaxation time τ and dissipation factor tan δ were determined. The analysis of the optical absorption data revealed that the optical band gap Eg was indirect transitions. The optical dispersion parameters Eo and Ed were determined according to Wemple and Didomenico method.