Structural and optical properties of terbium in TiO2 matrix

TiO2 thin films doped with different concentration of Tb have been prepared and study of terbium photoluminescence in TiO2 host has been presented. Thin films were deposited on silicon and SiO2 substrates by magnetron sputtering of Ti–Tb mosaic target in oxygen atmosphere. XRD examinations show nanocrystalline nature of prepared thin films with TiO2-anatase and -rutile phases depending on concentration of Tb. Optical transmission study has shown the red shift of the fundamental absorption edge of TiO2 with the increase of terbium content in the thin film. Also, the transparency decreased with increasing in amount of Tb. Photoluminescence (PL) spectra, measured upon UV excitation at 302 nm at room temperature, show a dominating green luminescence corresponding to 5D4-7F5 transition at 545 nm for TiO2-rutile thin film with 2.6 at.% of Tb. The superposition of PL peaks from Tb and TiO2 host matrix was also observed at 491 nm.