Abstract
Ga-doped TiO2 films were prepared by spin-coating method and optical properties of non-doped and Ga-doped TiO2 films were investigated. In the films prepared using low concentration of Ga to Ti in the solution, few Ga2O3 crystals existed in the TiO2 films. The thickness of Ga-doped TiO2 films increased and the refractive index of the films decreased with increasing the ratio of Ga to Ti in the solution. In the reflectance measurements, there was little dependency of doping concentration as long as the concentration was not too high. The transmittance increased with increasing the ratio of Ga to Ti in the solution. The bandgap of the non-doped and Ga-doped TiO2 films were obtained using absorption coefficients calculated with reflectance and transmittance spectra. The bandgap of the films was almost constant regardless of the ratio of Ga to Ti in the solution.
