Electronic structure and optical properties of Fe-doped TiO2 by ab initio calculations

We investigate the electronic structure and the optical characterizations of iron incorporating titanium dioxide by ab initio method by employing the density functional theory. We show that Fe atoms can be incorporated into TiO2 by replacing Ti atoms in the crystal structure of FexTi1−xO2 according to the ratio X=0.00, 0.25, 0.50, 0.75 and 1.00. The partial density of state and the energy band structure of the optimized structure have been calculated. Adding Fe atoms to the TiO2 causes shrinkage of the bands in the band structure that leads to a decrease in the energy gap of the pure titanium dioxide crystal structure. The results of the optical properties showed that the titanium dioxide has no absorption in the range of the visible light and detect only in the ultraviolet light (UV). The optical constant absorption coefficient, reflectivity and real and imaginary parts of the dielectric constant have been calculated. It exhibits that the properties of pure TiO2 will change by adding the Fe atoms to the structure, which leads to a significant enhancement in the optical characteristics.