The de-clustering influence of aluminum ions on the emission features of Nd3+ ions in PbO–SiO2 glasses

Abstract Nd 3+ doped lead alumino silicate glasses with varying concentration of Al 2 O 3 (from 5 to 10 mol%) have been synthesized. The IR and Raman spectral studies of these glasses have indicated that there is a gradual increase in the depolymerization of the glass network with increase in the concentration of Al 2 O 3 . The optical absorption, luminescence spectra and fluorescence decay curves of these glasses were recorded at room temperature. From these studies, the radiative parameters viz., spontaneous emission probability A , the total emission probability, the radiative lifetime τ , the fluorescent branching ratio β of different transitions originated from 4 F 3/2 level of Nd 3+ ions have been evaluated. A clear increase in the quantum efficiency and luminescence emission of the two prominent NIR bands of Nd 3+ ions viz., 4 F 3/2 → 4 I 11/2, 13/2 , is observed with increase in the concentration of Al 2 O 3 . The increase has been attributed to the possible admixing of wavefunctions of opposite parities and due to the declusterization of Nd 3+ ions by Al 3+ ions in the glass network.