Up-conversion of Er3+/Yb3+ co-doped transparent glass-ceramics containing Ba2LaF7 nanocrystals

Abstract The up-conversion of Er 3+ /Yb 3+ co-doped transparent glass-ceramics 50SiO 2 -10AlF 3 -5TiO 2 -30BaF 2 -4LaF 3 -0.5ErF 3 -0.5YbF 3 containing Ba 2 LaF 7 nanocrystals under the changing of heat treatment temperature and time were investigated. The Ba 2 LaF 7 nanocrystals precipitated from the glass matrix was confirmed by X-ray diffraction (XRD). The structural investigation carried out by XRD and transmission electron microscopy (TEM) evidenced the formation of cubic Ba 2 LaF 7 nanocrystals with crystal size of about 14 nm. Comparing with the samples before heat treatment, the high efficiency up-conversion emission of Er 3+ /Yb 3+ co-doped samples was observed in the glass-ceramics under 980 nm laser diode excitation. The increase in red emission intensity bands was stronger than the green bands when the crystal size increased. The mechanism for the up-conversion process in the glass-ceramics and the reasons for the increase of Er 3+ /Yb 3+ co-doped up-conversion intensity after heat treatment were discussed.