Optical characterization and γ-irradiation response of conductive transparent oxide of SnO2:Sb films

Abstract

We are concerned in synthesizing conductive transparent oxide (CTO) films by spray pyrolysis deposition (SPD) for SnO2 (undoped) and SnO2:Sb (doped) film. The average value of the optical energy gap for CTO films of SnO2 and SnO2:Sb were found 4.01and 3.92 eV, respectively for direct transition before gamma irradiation. The optical conductivity of undoped and doped CTO film was calculated 8 × 1014 and 24 × 1014 Ω-1cm-1, respectively. The average value of refractive index for SnO2 and SnO2:Sb films was found 1.93 and 1.67, respectively at 0.0 kGy. The average value of refractive index of annealed SnO2:Sb films was decreased from 2.07 to 1.55 after γ-irradiation (22.0 kGy). The values of real part for the thermal annealed SnO2:Sb films were found positive before and after γ-irradiation in Vis-NIR range; accordingly the thin film material is said to have an intrinsically capacitive optical response. The imaginary part values of annealed SnO2:Sb film were decreased after γ-irradiation (22.0 kGy) in Vis-NIR range but still have positive value; so the material is said to have a resistive optical response. The optimum contact angle of doped CTO films was found 30° with hydrophilic surface. This property of CTO could be applied as covers for solar cells and other devices to keep its efficiency during rains and high humidity.