Judd-Ofelt analysis and luminescence studies on Dy3+ -doped different phosphate glasses for white light emitting material applications

This article reports detailed analysis of trivalent dysprosium (Dy3+) doped alkali and alkaline earth phosphate glasses prepared by melt quenching technique. From X-ray diffraction, Scanning electron microscope and P-31 solid-state NMR spectral investigations, the structural properties have been evaluated. The optical absorption spectra of these Dy3+ doped phosphate glasses have been analyzed and discussed using Judd-Ofelt (J-O) theory and intensity parameters have been evaluated. Different radiative parameters such as radiative lifetimes (tau(R)), branching ratios (beta(r)) and emission cross sections (sigma(P)) have been calculated in all the alkali and alkaline earth phosphate glasses and compared. Emission from F-4(9/2) state has been identified and the measured lifetimes have been obtained from the decay curves and compared with calculated lifetime values. The CIE chromaticity co-ordinates have been measured from the photoluminescence spectra.