Luminescence and energy transfer in Dy 3+ /Tb 3+ co-doped transparent oxyfluorosilicate glass-ceramics for green emitting applications

Abstract Transparent oxyfluorosilicate glass-ceramics containing cubic SrF 2 nanocrystals doped with Dy 3+ , Tb 3+ , and Dy 3+ /Tb 3+ were successfully synthesized by melt quenching followed by heat treatment process. The crystalline phase of SrF 2 nanocrystals during heat treatment was confirmed by X-ray diffraction. The emission intensity of glass-ceramics is much stronger than that of their parent glasses, on the one hand due to progressive incorporation of Dy 3+ and Tb 3+ ions within the SrF 2 nanocrystals, on the other hand due to an efficient energy transfer from Dy 3+ to Tb 3+ . Luminescence quantum efficiency of the samples was measured by using an integrating sphere. Luminescence decay curves of the 4 F 9/2 level were fitted to Inokuti-Hirayama (IH) model for analyzing the energy transfer rates between Dy 3+ and Tb 3+ ions. The chromaticity coordinates were determined from the measured emission spectra and they are located at the green and white light regions.