Near-infrared quantum cutting in Pr3+-Yb3+ Co-doped oxyfluoride glass ceramics containing CaF2 nanocrystals

The Pr3+-Yb3+ co-doped oxyfluoride glass-ceramics containing CaF2 nanocrystals were obtained by thermal treatment on the as-made glasses. The structure of fluoride nanocrystals was investigated. The light-emitting mechanism of Pr3+-Yb3+ in the near infrared region was proposed and the fluorescence lifetime and quantum efficiency was calculated. The results indicate that the main phase in the oxyfluoride glassceramics is CaF2 nanocrystal sized at 30 nm. Energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) have proved the incorporation of Pr3+ and Yb3+ into CaF2 nanocrystal lattice. Near-infrared quantum cutting involving Yb3+ 980 nm and 1 015 nm (F-2(5/2)->(2) F (7/2)) emission has been achieved upon the excitation of the (3) P (0) energy level of Pr3+ at 482 nm. The fluorescence lifetime decreases sharply and quantum efficiency increases with increasing Yb3+ concentration, and the optimal quantum efficiency reaches 191%.