FT-IR, FT-Raman and fluorescence studies of Tb3+ ions activated lead containing sodium fluoroborate glasses

This study reports on the concentration dependent fluorescence properties of Tb3+-doped lead containing calcium zinc sodium fluoroborate (LCZSFB) glasses and are analyzed by DSC, FT-IR, FT-Raman, optical absorption, emission and decay curve spectra. Co-existence of trigonal BO3 and tetrahedral BO4 units was evidenced by FT-IR and Raman spectroscopy. Judd-Ofelt theory was applied to the experimental oscillator strengths to evaluate the J-O intensity parameters. The fluorescence spectra of Tb3+-doped glasses have revealed prominent blue and green emissions originating from D-5(3) and D-5(4) excited levels to F-7(J) ground state multiplet, respectively. The luminescent intensity of the transitions originating from D-5(4) state increases with increase of Tb3+ concentration and no quenching effect is noticed up to 2 mol% of Tb3+ ions. Chromaticity color coordinates have been calculated and the dominant emission in the green region is discussed. The nature of decay curves of D-5(4) level for different Tb3+ ion concentration in all LCZSFB glasses has been analyzed. Using the J-O intensity parameters as well as from the emission and decay curve measurements, various radiative and fluorescence properties have been calculated for the D-5(4) fluorescent level. Based on these results, the utility of Tb3+ ions doped LCZSFB glasses as laser active materials for high intensity emissions in the green region is discussed. (C) 2012 Elsevier B.V. All rights reserved.