Iron Doped Titania Thin Films Prepared by Spin Coating

Thin films of titania (TiO2) doped with 1–5 wt-%Fe were spin coated on glass slides and then annealed at 500°C for 2 h. Results revealed that all of the films were ∼500 nm in thickness and consisted of anatase. Increasing the dopant levels revealed the following trends: the major (101) anatase peak shifted to larger lattice spacing [the peaks were normalised using the principal (210) chromium coating peak as an in situ standard]; the microstructures showed increasing shrinkage cracking, a phenomenon that has not been reported previously; the optical transmittance generally decreased; the amplitude of the transmittance curves generally decreased; and the optical indirect band gap decreased from 3.40 to 3.18 eV, possibly due to silicon contamination, residual thermal stress and/or the formation of midgap states from Fe-doping

Fe-Doped and Mn-Doped Titanium Dioxide Thin Films

Thin films of TiO2 doped with Fe and Mn were deposited on F-doped SnO2-coated glass by spin coating. Dopant concentrations of 3–7 wt% (metal basis) were used. The structural, chemical, and optical characteristics of the films were investigated. Laser Raman microspectroscopy and glancing angle X-ray diffraction data showed that the films consisted of the anatase polymorph of TiO2. X-ray photoelectron spectroscopy data ndicated the presence of Fe3+, Mn4+, and Mn3+ in the doped films, as predicted by calculated thermodynamic stability diagrams, and the occurrence of atomic disorder and associated structural distortion. Ultraviolet–visible spectrophotometry data showed that the optical indirect band gap of the films decreased significantly with increasing dopant levels, from 3.36 eV (undoped) to 2.95 eV (7 wt% Fe) and 2.90 eV (7 wt% Mn). These improvements are attributed to single (Fe) or multiple (Mn) shallow electron/hole trapping sites associated with the dopant ions

Effect of Fe doping on TiO2 films prepared by spin coating

Iron-doped titanium dioxide thin films were coated on fluorine-doped tin oxide coated glass using the spin coating technique. The concentration of the dopant was varied up to 7 mol% iron (metal base). The films were characterised for their structural, morphological, and optical properties. Glancing angle X-ray diffraction and laser Raman microspectroscopy indicate that the films consisted solely of the anatase polymorph of titanium dioxide, without any contamination phases, such as iron oxide. Field emission scanning electron microscopy indicates that the films were microstructurally homogeneous and fully dense, with grains in the size range of ∼10–20 nm. UV-VIS spectrophotometry shows that the optical indirect band gap of the films decreased with increasing iron doping (3.36 eV for undoped and 2.95 eV for 7 mol% Fe)