Influence of Fe3+ ions doping on TiO2 thin films: Defect generation, d-d transition and band gap tuning for optoelectronic device applications

Abstract

In this article, we have explored the influence of Fe3+ ion on the surface morphological, structural, optical and electrical properties of TiO2 thin films grown on glass substrates by thermal spray pyrolysis technique. The FESEM micrographs of the deposited TiO2 thin films reveal that the surface consists of agglomerates of small grains. The anatase and rutile phase is confirmed by XRD and Debye-Scherer (D-S), Uniform Deformation Model (UDM) and Halder-Wagner (HW) method are employed to determine the structural parameters using XRD peak profile analysis. A red shift occurs in absorption spectra and band gap decreases with Fe content. The optical parameters such as skin depth, optical static dielectric constant, Urbach energy, etc and Electron-phonon interaction are increased with increasing Fe contents, whereas steepness parameter decreases. The electrical properties are studied by Hall Effect measurements. The paramount study is useful for standardizing the Fe-doped TiO2 thin films for optoelectronic device applications.