Fluorescence characterization of heavily Eu3+-doped lanthanum gallate glass spheres with high quenching concentration.

Highly Eu2O3-doped (up to 30 mol%) La2O3-Ga2O3 glasses were synthesized by an aerodynamic levitation technique. The red emission associated with D05 level of Eu3+was most intense at 20 mol% Eu2O3, indicating a small effect of concentration quenching even at high Eu concentration. The fluorescence decay curves indicated that the dominant transition mechanism at high Eu concentration was fast energy migration among the Eu3+ ions, which averaged the environment of the Eu, yielding a nearly single-exponential decay of D05→F27 emission. Lifetime of the D05 level gradually decreased with Eu2O3 over the 5-25 mol% and rapidly decreased at 30 mol%, very consistent with the observed emission spectra.