The Effect of Indium Doped SnO2 Thin Films on Optical Properties Prepared by Sol-Gel Spin Coating Technique

This study aims to investigate the optical properties of SnO2 thin films doped with Indium synthesized using the sol-gel spin coating technique. The optical properties of thin films were measured using Thermo Scientific GENESYS UV-Vis Spectrophotometer. The results of characterization of optical properties showed that the thin films of Indium doped SnO2 experienced an increase in transmittance from 75 - 96.6% at wavelengths 300 - 350 nm and increased maximum absorbance at a wavelength of 300 nm from 3.19 - 4.32 with an increase in doping percentage. This shows that thin films absorbance the maximum wave at a wavelength of 300 nm. Increasing the percentage of doping causes the thin films of SnO2 to experience a decrease in energy gap both in the direct energy gap of 3.64 - 3.57 eV and indirect energy gap i.e from 3.92 - 3.87 eV. The optical activation energy of the SnO2 thin films decreased with increasing doping percentage from 2.91 - 2.35 eV. The results of this study indicate that SnO2: In thin films is high-quality because it has high transmittance and low energy gap.