Kinetics of luminescence of interface defects and resonant Er3+ ions in nanostructured SnO2:SiO2

Silica glass with SnO2 nanocrystals and Er3+ ions are prepared by the sol–gel route and treatment above 1000 °C. Transmission electron microscopy evidences a homogeneous dispersion of nanoclusters 4–6 nm in size in the amorphous silica matrix. Photoluminescence spectra excited at 3.5 eV, outside erbium transitions, show an inhomogeneous spectral distribution of light emission from interface defects, in the range 1.9–2.4 eV, resonant with transitions of erbium ions. The analysis of kinetics and temperature dependence of luminescence allows to quantify the efficiency of the energy transfer channel between nanoclusters and erbium ions.