Synthesis and Optical Studies on Concentration Dependent Dy3+ Doped Lithium Fluoroborate Glasses for W-LED Applications

Abstract

A new series of Dy3+ doped Lithium fluoroborate glasses with the chemical composition (40–x)B2O3 + 20ZnO + 20NaF + 20Li2O + xDy2O3 (where x = 0.1, 0.3, 1.0, 2.0 and 3.0 wt%) were prepared following conventional melt quenching technique and characterized using XRD, FTIR, optical absorption and luminescence measurements. The XRD pattern of the prepared glasses confirms the amorphous in nature. The fundamental stretching vibrations of various borates (BO3, BO4) were identified through the FTIR analysis. From the UV-Vis-NIR spectra, the oscillator strength and bonding parameter were calculated. The ionic bond nature of the prepared glasses were identify from their negative sign of δ. The luminescence spectra exhibit two visible bands 4F9/2→6H15/2 (Blue) and 4F9/2→6H13/2 (Yellow) respectively. The radiative properties such as peak wavelength and effective band width for the 4F9/2→6H15/2 and 4F9/2→6H13/2 emission transition were calculated. The decay lifetime of the 4F9/2 level has been measured from the decay profiles and compared with the calculated lifetimes. The yellow to blue (Y/B) ratios and color coordinates have been calculated from the luminescence spectra and the utility of the present glasses for white light emitting diodes (W-LEDs) applications.