Effects of heat treatment and Yb3+concentration on the downconversion emission of Er3+/Yb3+co-doped transparent silicate glass-ceramics

Abstract

The SiO2-Al2O3-BaF2-TiO2-CaF2transparent silicate glass-ceramics containing BaF2 nanocrystals were successfully prepared by heat treatment process through conventional melting method. Effects of heat treatment processes and Yb3+ concentration on the downconversion (DC) emission of the co-doped Er3+/Yb3+ transparent silicate glass-ceramics were investigated. With the increase of temperatures and times of heat treatment process, the DC emission intensity of the co-doped Er3+/Yb3+ glass-ceramics was signifcantly enhanced. At the same time, with the increase of Yb3+ concentration, the value of DC intensity of Er3+/Yb3+ co-doped bands centered at 849, 883 and 1533 nm is maximized when the concentration of Yb3+ reaches 2.5 mol.%. When the concentration exceed 2.5 mol. %, the DC emission intensity of Er3+/Yb3+ co-doped bands centered at 849, 883 and 1533 nm was decreased, owing to the self-quenching effect. It's interesting that the DC emission intensity of Er3+/Yb3+ codoped band centered at 978 nm didn't quench when the Yb3+ concentration exceed 2.5 mol. %. At the same time, the DC mechanism and ET processes between Yb3+ and Er3+ ions were discussed.