Effects of heat treatment and TiO2 content on the optical properties of Eu3+ doped TiO2–SiO2 thin films

The photoluminescence properties of Eu3+-doped TiO2–SiO2 thin films were investigated. The films were deposited on silicon substrates by the sol–gel process using the dip-coating method. The molar ratio of TiO2 content was varied from 25% to 100%, while Europium concentration was fixed to 1%. The obtained films were calcinated at various temperatures ranging from 400 °C to 1300 °C, which allowed determining the optimal conditions for the Eu3+ luminescence. Meanwhile, the structure of TiO2–SiO2 powders, prepared in the same conditions as the films, was also studied by Raman spectroscopy. It revealed the role of Europium and SiO2 on the stabilization of the anatase phase and the importance of the silica matrix in the control of titania particle size.