Preparation and luminescence properties of Ce3+ and Tb3+ co-doped glasses and glass ceramics containing SrF2 nanocrystals

The Ce3+ and Tb3+ co-doped glasses and glass ceramics containing SrF2 nanocrystals were prepared by melt-quenching and subsequent heat treating and their luminescence properties were described. The formation of SrF2 nanocrystals in glass ceramics was confirmed by X-ray diffraction and transmission electron microscopy. The XRD patterns and photoluminescence spectra revealed that the Ce3+ ions and Tb3+ ions have been incorporated into SrF2 nanocrystals. The decay time of excited states has been used to reveal the energy transfer mechanism between Ce3+ and Tb3+. The emission intensity of Tb3+ ions in the glass ceramics was much stronger than that in the precursor glass, which could be ascribed to the more efficient energy transfer from Ce3+ to Tb3+ in the glass ceramics due to the enrichment of Ce3+ and Tb3+ ions and the shortening of the distance between Ce3+ and Tb3+ ions in the precipitated SrF2 nanocrystals. The glasses and glass ceramics could emit bright green light by adjusting concentration ratio of Ce3+ to Tb3+ and heat treatment temperature.