Time-resolved fluorescence line-narrowing and lifetime studies of gel-derived Eu 2 O 3 -Al 2 O 3 -SiO 2 systems

Abstract

Time-resolved, fluorescence line narrowing (FLN) spectra and fluorescence lifetimes are used to characterize local structure in Eu 3+ -doped silica gels. Co-doping with Al 3+ is shown to have a significant effect on the local structure of the Eu 3+ ion in the silica matrix. A pulsed dye laser was used to selectively excite subsets of ions contributing to the inhomogeneously broadened 7 F O $ARLR 5 D O transition. Resultant line-narrowed fluorescence spectra and lifetimes are interpreted in terms of site symmetry, energy transfer, Eu 3+ ion clustering, and residual hydroxyl groups.