Structure and photoluminescence properties of sol–gel TiO2–SiO2 films

TiO2–SiO2 films (Ti/Si=1:1) have been prepared by the sol–gel method. The structure and photoluminescence (PL) properties of the films heat-treated at different temperatures have been investigated. The films appear composed of TiO2 nanocrystallites in anatase form embedded in SiO2-rich matrix. Emission bands are observed in all the heat-treated films. This PL is attributed to various defects resulting from thermal treatment and crystallization of TiO2 and to energy levels in the mixed oxide matrix.