Synthesis and luminescence properties of novel red-emitting Eu3+ ions doped silicate phosphors for photonic applications

In the present work, we report on luminescence properties of Eu3+ ions doped KBaScSi3O9 silicate phosphors (KBSS) synthesized by high temperature solid state reaction method and the prepared phosphor samples were characterized through XRD, FE-SEM, photoluminescence and decay spectral measurements. The XRD pattern confirmed that the KBSS host lattice exhibited a monoclinic crystal structure. Room temperature photoluminescence (PL) spectroscopic results reveal that, on Eu3+ ion doping in the KBSS host matrix, the magnetic dipole transition (D-5(0) -> F-7(1)) at 593 nm responsible for orange light, dominates the red emission with respect to the electric dipole transition (D-5(0) -> F-7(2)) at 611 nm. The Judd-Ofelt (JO) intensity parameters Omega(lambda) (lambda = 2 and 4) have been calculated from the emission spectra to understand the nature of ligand environment around the Eu3+ ions. The radiative parameters, such as transition probability (A), stimulated emission cross-section (sigma(E)(P)), radiative lifetime (tau(R)) and branching ratios (beta(R)) corresponding to the D-5(0)-> F-7(0), D-5(0)-> F-7(1), D-5(0)-> F-7(2), D-5(0)-> F-7(3) and D-5(0)-> F-7(4) emission transitions have been determined by using JO parameters and the refractive indices respectively. The concentration quenching effect for Eu3+ was found at the optimum doping concentration of 7 mol %. The CIE chromaticity coordinates were calculated from the luminescence spectra to explore the dominant emission colour of the title phosphors. The experimental lifetime values of D-5(0) level of the Eu3+ doped silicate phosphors have been calculated and the obtained results were discussed in detail. (C) 2020 Elsevier B.V. All rights reserved.