Temperature dependence of optical and electrical properties of gamma-irradiated indium oxide thin film

Abstract

In2O3 thin films were grown on glass substrates by spray pyrolysis using InCl30.4 H2O as the solute. The precursor solution of concentration 0.2 M was sprayed on substrates at two different substrate temperatures, 4000 C and 4500 C. The deposited films were exposed to different doses of gamma radiation. The optical and electrical characterisations of the irradiated layers were done to evaluate transmittance, optical bandgap, Urbach energy, resistivity and other optical and electrical parameters. Transmittance varied with irradiation and it increased with deposition temperature. Bandgap energy increased with irradiation up to a particular dose and then decreased for both higher temperature and lower temperature samples. But the critical dose for this bandgap reversal is higher for samples deposited at a higher temperature. Urbach energy shows an inverse relation with the bandgap. The refractive index is estimated using three different models and the extinction coefficient evaluated for the deposited samples. Resistivity also increased up to the same critical dose of 200 Gy for lower temperature samples and 300 Gy for higher temperature samples. The substrate temperature effect on the electrical and optical properties of gamma irradiated In2O3 thin film was studied in detail.