Tailoring the luminescence of Eu3+ co-doped Dy3+ incorporated aluminofluoro-borophosphate glasses for white light applications

Co-doping of Eu3+ ions in Dy3+ single doped glasses improves white light emission. This manuscript reports correlation between the structural rearrangement and its effect on the optical properties of the title glasses. The nephelauxetic effect on absorption transitions have been used to elucidate the bonding nature of the RE3+ ions with their surrounding ligands. It reveals the predominant ionic nature of the dysprosium bonds while that of Eu ions exhibit covalent nature. Effect of Eu3+ ions on the symmetry of the ligand field around the Dy3+ ions have been predicted using JO theory and asymmetric (Y/B) intensity ratio. It is found that asymmetry around Dy3+ ions increases with Eu3+ ions concentration. Tuneable nature of the white light emission from the Eu3+/Dy3+ co-doped aluminofluoro-borophosphate glasses was confirmed through the CIE 1931 chromaticity coordinates for glasses containing different concentrations of europium. The energy transfer process takes place between Dy3+ and Eu3+ ions has also been confirmed through lifetime measurements. Fitting the decay curves using IH model thus reveal the dipole-dipole nature of interaction.