Temperature-dependent luminescence and energy transfer in Europium and rare earth codoped nanostructured sol-gel SiO₂ glasses

Temperature- dependent luminescence spectra, lifetimes and energy transfer in Eu³⁺ and other rare earths (La³⁺, Pr³⁺, Nd³⁺, Sm³⁺, Gd³⁺, Dy³⁺, Er³⁺ & Yb³⁺) codoped sol-gel SiO₂ glasses, were investigated in the temperature range from 10K to 300K. Due to the addition of the other rare earths as co-dopants, luminescence spectra of Eu³⁺ have shown significant changes not only in spectral intensities but also in emission peak features. Evaluation of the temperature- dependent energy transfer rates and lifetimes and the computation of critical energy transfer distances by employing two different energy transfer model schemes, have provided evidence for such luminescence behavior in the nanometer-size confined glass matrices.