Structural and optical properties of Fe-doped TiO2 films by sol–gel method

Abstract

Fe-doped TiO2 films were prepared by sol–gel spin coating method. After annealing in vacuum, the structural and optical properties of the films were investigated. XRD patterns revealed that all diffraction peaks can be attributed to TiO2 with anatase phase structure. No segregated phases are present in the samples within XRD detection limit. XPS results indicated that iron element exists in a tervalent state and incorporates into TiO2 lattice. Raman spectra demonstrated that all the films are in pure anatase phase. No other vibration modes in the spectra were detected. Raman spectra are consistent with the results of XRD patterns. Photoluminescence spectra at room temperature are sensitive to the concentration of Fe doping. The quenching increases with the increase in amount of dopant, which can be due to the introduction of defect sites such as oxygen vacancy by Fe doping. The free hole can interact with a trapped electron, or a free electron can interact with a trapped hole, resulting in non-radiative.