Effect of Fe doping on the microstructure, optical and dispersion energy characteristics of TiO2 thin films prepared via spray pyrolysis technique

In this study, we have delineated the preparation and influence of Fe doping on microstructural and optical properties of the undoped and Fe -doped TiO2 thin film with different Fe concentrations (0, 2, 4, 6, and 8 at.%). The samples are prepared by a simple and cost-effective spray pyrolysis technique (SPT) using Ti (OCH2CH2CH2CH3)4 as a precursor of mother material. The effect of Fe on the microstructure and phase formation of TiO2 thin films is investigated by XRD analysis. XRD investigation depicts that the undoped product corresponds to anatase phase of TiO2 and remains uncontaminated with addition of 2 at.% Fe impurity. It is also observed that Fe introduces a phase transition from anatase to rutile after adulterating more Fe contents (4, 6 and 8 at.%). In order to study the optical characteristics, UV-vis spectroscopy has been employed, which reveals that UV absorption for the Fe incorporated TiO2 products are observed to move to a longer wavelength (red shift) and lower bandgap energy from 3.81 eV (0 at.% Fe) to 3.70 eV (8 at.% Fe) of the TiO2 thin films. The optical constants such as refractive index, complex dielectric constants, tan delta, volume energy loss (VELF) and surface energy loss (SELF) functions, dispersion parameters of synthesized titanium dioxide samples has been studied. The results of optical constant values and the dispersion enegy parameters depicts the influence of Fe on microstructural and optical transportation properties of the as prepared samples more appropriately and effectively.