Microstructure and photoluminescence properties of sol–gel Y2−xErxTi2O7 thin films

Abstract Optically active Y2−xErxTi2O7 (YETO) thin films have been successfully deposited using the aerosol–gel process. The effects of post-deposition rapid thermal annealing and conventional thermal annealing heat-treatments have been investigated. The corresponding thin film microstructure is described and discussed in terms of crystallisation degree, mean crystallite size, and porosity. Strong photoluminescence (PL) at 1.53 μm is observed under 980 nm excitation. PL properties are found to depend closely on the film crystallisation degree. PL emission spectra exhibit sharp peaks for crystalline films and a wide band for amorphous ones. PL decay curves are also very closely related to the film microstructure and the corresponding lifetimes range between 2 and 7 ms for a similar erbium concentration.