Structural, optical, photoluminescence and photocatalytic investigations on Fe doped Tio2 thin films

Pure and Fe doped TiO2 thin films were deposited onto quartz substrates maintained at room temperature by
radio frequency magnetron sputtering. The films were annealed at 873 K in air for 2 h and characterized using
X-ray diffraction (XRD), micro Raman spectroscopy, Scanning electron microscopy (SEM), Energy dispersive
spectroscopy, ultraviolet-visible and photoluminescence (PL) spectroscopy. Pure TiO2 thin films were XRDamorphous,
but micro Raman spectra revealed the presence of anatase phase. Doping with Fe has influenced
the transformation of films to anatase phase. Improved crystallinity was observed in the 0.1 at% Fe doped
films, where the lattice constants approached the values for bulk anatase TiO2, and the films showed minimum
strain. At higher Fe concentrations, micro Raman spectra revealed the presence of rutile phase also. SEM images
revealed crack free surface and surface roughness was found to increase with increase in Fe concentration. Dopingwith
Fe has resulted in a red shift of absorption edge. PL emission intensitywas found to increase with Fe concentration,
but at higher concentrations quenching of PL emission was observed. Fe doping resulted in
enhancement of photocatalytic activity, evaluated by monitoring the degradation of methylene blue solution.
0.8 at% Fe doped TiO2 films exhibited the highest photocatalytic activity.