Spectroscopic properties of P2O5–MgO–Na2O:Dy2O3 glasses for the applications of W-LEDs

P2O5–MgO–Na2O glasses with varied concentrations of (RE) Dy3+ ions (Dy2O3: 0.5, 1.0, 1.5, and 2.0 mol percent) were prepared by melt quenching technique. The prepared glass samples have been characterized using XRD and SEM techniques and the amorphous nature of the samples was ensured. Optical absorption and photoluminescence spectra and also decay characteristics were recorded. Using absorbance spectra, the J-O parameters Ω2, Ω4, and Ω6 were calculated for the glass doped with 1.0 mol % of Dy2O3. Several radiative parameters such as radiative probability, AR, radiative lifetime τR, branching ratio, βR, emission cross-section, σEP for Dy2O3 doped glasses were evaluated and reported using the emission spectra. The quantum efficiency of 1.0 mol% Dy2O3 doped glass was determined to be 86%, which is observed to be the largest when compared to that of all other glasses. The color chromaticity co-ordinates were observed to move towards white region as the concentration of Dy2O3 is increased. The quantitative analysis of these data in commination with results of infrared spectral investigations, revealed that the 1.0 mol % of Dy3+ ions is optimal concentration for achieving the highest luminescence efficiency.