Preparation and upconversion luminescent properties of Yb3+/Er3+ doped transparent glass-ceramics containing CaF2 nanocrystals

Yb3+/Er3+ doped high-fluoride glass-ceramics were prepared by the high-temperature melting method. The crystal morphology and structure of the rare-earth doped glass-ceramics were characterized by X-ray diffraction, infrared spectra, and high-resolution transmission electron microscope. The influence of crystal size and distribution on the transmittance of glass-ceramics was analyzed. The upconversion emission intensity of the rare earth doped glass-ceramics at different heat treatment temperatures was evaluated. It is shown that the precipitation of CaF2 crystals greatly improves the upconversion emission efficiency of rare earth ions. By analyzing different high-power pump lasers and corresponding up-conversion luminous intensities, the mechanism of up-conversion luminescence of this material is further elaborated.