Concentration dependence of luminescence efficiency of Dy3+ ions in strontium zinc phosphate glasses mixed with Pb3O4

In this work we synthesized SrO–ZnO–P2O5 glasses mixed with Pb3O4 (heavy metal oxide) and doped with different amounts of Dy2O3 (0.1 to 1.0 mol%). Subsequently their emission and decay characteristics were investigated as a function of Dy2O3 concentration. The emission spectra exhibited three principal emission bands in the visible region corresponding to 4F9/2  6H15/2 (482 nm), 6H13/2 (574 nm) and 6H11/2 (663 nm) transitions. With increase in the concentration of Dy2O3 (upto 0.8 mol%) a considerable increase in the intensity of these bands was observed and, for further increase, quenching of photoluminescence (PL) output was observed. Using emission spectra, various radiative parameters were evaluated and all these parameters were found to increase with increase in Dy2O3 concentration. The Y/B integral emission intensity ratio of Dy3+ ions evaluated from these spectra exhibited a decreasing trend with increase in the Dy2O3 concentration up to 0.8 mol%. Quenching of luminescence observed in the case of the glasses doped with 1.0 mol% is attributed to clustering of Dy3+ ions. The quantitative analysis of these results together with infra-red (IR) spectral studies indicated that 0.8 mol% is the optimum concentration of Dy3+ ions needed to achieve maximum luminescence efficiency. Copyright © 2016 John Wiley & Sons, Ltd.