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 KBaScSi 3 O 9 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 (5D 0 → 7F 1) at 593 nm responsible for orange light, dominates the red emission with respect to the electric dipole transition (5D 0 → 7F 2) at 611 nm. The Judd-Ofelt (JO) intensity parameters Ω λ (λ = 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 ( σ P E ), radiative lifetime (τ R) and branching ratios (β R) corresponding to the 5D 0 →7F 0 , 5D 0 →7F 1 , 5D 0 →7F 2 , 5D 0 →7F 3 and 5D 0 →7F 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 5D 0 level of the Eu3+ doped silicate phosphors have been calculated and the obtained results were discussed in detail. Image 1 • Higher Ω 2 values indicate the higher asymmetry around the Eu3+ ion site. • CIE 1931 diagram confirms that studied phosphors give red emission when excited at 466 nm. • KBSS:xEu phosphors excited at 466 nm shows a very high color purity in the range of 97.4%–98.8%. • 5D 0.→7F 2 of KBSS:0.07Eu phosphor exhibits higher A σ P E , β R values suitable for lasers. [ABSTRACT FROM AUTHOR]