Luminescence concentration quenching and site-occupancy of Eu 2+ ions in Na 2 Ca 2 Si 3 O 9 phosphors derived from 45S5 glass-ceramics

Abstract The phosphors of Na 2 Ca 2-2 x Eu 2 x Si 3 O 9 ( x = 0, 0.03, 0.05, 0.07, 0.09) were first synthesized by sol-gel method. The crystal phase formations of the phosphors were detected by X-ray powder diffraction (XRD) measurements and the structure refinement. The photoluminescence spectra, the concentration quenching, the luminescence decay curves and the luminescence color chromaticity were measured, respectively. The excitation spectra indicate that the phosphors can be effectively excited by near UV-LED chips. Two kinds of Eu 2+ sites centered at 545 nm and 505 nm were discussed by analyzing the spectra, concentration-dependent luminescence intensity and lifetimes. This is a potential tool for monitoring the bioactivity of 45S5 glass-ceramics in situ.