Gd 3+ doping induced enhanced upconversion luminescence in Er 3+ /Yb 3+ co-doped transparent oxyfluoride glass ceramics containing NaYF 4 nanocrystals

In this article, transparent oxyfluoride glass ceramics containing β -NaYF4 nanocrystals were successfully prepared via Gd3+ doping. Compared to conventional non-doped glasses, the thermal treatment temperature required for the precipitation of β -NaYF4 nanocrystals can be lowered with the doping of Gd3+. Furthermore, under the same thermal treatment condition, more β -NaYF4 nanocrystals were precipitated in Gd3+ doped ones, which greatly improves the luminescence efficiency of rare earth doped glass ceramics. Possible mechanism for the Gd3+ doping induced enhanced upconversion luminescence phenomenon was proposed, based on thorough structural and optical characterizations. The results revealed that the doping of Gd3+ ions could decrease the crystallization activation energy and promote the formation of Y-F-Na bonding, which helps the precipitation of β -NaYF4 nanocrystals. Consequently, a large enhancement in upconversion luminescence was achieved. Moreover, the strategy can be successfully applied to the development of other glass ceramic systems for various optoelectronic applications.