Structure and spectroscopic properties of Tb3+/Sm3+ co-doped oxyfluoride glass ceramics containing LiYF4 nanocrystals

In this paper, transparent oxyfluoride glass ceramics containing LiYF4 nanocrystals were successfully synthesized by appropriate heat-treatment on the SiO2-Al2O3-YF3-LiF precursor glass. The average diameter of the LiYF4 nanocrystals is about 16 nm, which has been confirmed by XRD and TEM characterization. Compared with RE3+ (RE = Tb, Sm)-doped glasses, glass ceramics have shown stronger emission intensities due to most rare earth ions have entered LiYF4 nanocrystals with lower phonon energy. A combination of blue, green and orange-red emissions has emerged in Tb3+/Sm3+ co-doped glass ceramics, and white light emission could be realized by varying the proportions of Tb3+ and Sm3+ under UV light excitation. Furthermore, the concentration quenching effect and the Tb3+→Sm3+ energy transfer process were investigated in this paper. Our results indicate that the Tb3+/Sm3+ co-doped oxyfluoride glass-ceramics containing LiYF4 nanocrystals show great potential to achieve a white light emission.