Luminescent studies of Dy3+ ion in alkali lead tellurofluoroborate glasses

Abstract

Dy 3+ -doped alkali lead tellurofluoroborate (RLTB) glasses (R=Li, Na and K) were prepared by melt quenching technique. Judd–Ofelt theory has been used to evaluate the three intensity parameters Ω 2 , Ω 4 and Ω 6 from the experimental oscillator strengths. The photoluminescence spectra obtained by the excitation wavelength of 385 nm show four emission bands at 454, 483, 575 and 665 nm corresponding to the 4 I 15/2 → 6 H 15/2 and 4 F 9/2 → 6 H J/2 ( J =15/2, 13/2 and 11/2) transitions, respectively. The laser characteristic parameters like fullwidth at half maxima (FWHM), stimulated emission cross-sections ( σ e ), optical gain parameters ( σ e × τ exp ) and gain bandwidth parameters ( σ e ×FWHM) were determined. From the visible emission spectra, yellow to blue (Y/B) intensity ratios and chromaticity coordinates were also estimated. The lifetimes of 4 F 9/2 metastable state were also measured and discussed. ► RLTB system is a novel host for optical absorption and luminescence studies. ► KLTB glass exhibits a greater degree of covalency for Dy–O bond. ► Decay curves of 4 F 79/2 state show bi-exponential behaviour in all the glasses. ► Dy 3+ doped RLTB glasses are the good materials for solid state lasers. ► Dy 3+ : RLTB glasses are suitable materials for white light emission.