Up- and down-conversion luminescence in the oxyfluoride glass ceramics containing Ba_(2+1.5x)Yb_(1-x)F_7:Tb~(3+) nanocrystals

摘要

Transparent oxyfluoride borosilicate glass ceramics containing Ba_(2+1.5x)Yb_(1-x)F_7:Tb~(3+) nanocrystals were successfully prepared by a melt-quenching method with subsequent heat treatment. The precipitated crystalline phase in the glass matrix changed gradually from BaF_2 to Ba_(2+1.5x)Yb_(1-x)F_7 with the increase of YbF_3 content, which was confirmed by the results of XRD, HRTEM and EDX measurements. The ultraviolet and visible up-conversion and near-infrared quantum cutting down-conversion emissions were observed and interpreted. These materials could be used to modify the solar spectrum and enhance the silicon solar cell efficiency by the up-conversion and down-conversion luminescence of Tb~(3+)-Yb~(3+) couples in the oxyfluoride borosilicate glass ceramics.