Eu3+ and Er3+ doped NaLu1−xYbxF4 (x = 0 ∼ 1) solid-solution self-crystallization nano-glass-ceramics: Microstructure and optical spectroscopy

NaLu1−xYbxF4 solid-solution nanocrystals embedded glass ceramics were successfully fabricated via the glass self-crystallization route for the first time. Importantly, the Eu3+ or Er3+ dopants are demonstrated to enter into the crystalline lattice by scanning transmission electron microscopy mapping and optical spectroscopy analysis. Further crystallization treatment is advantageous to improving the crystallinity and reducing surface-to-volume of NaLu1−xYbxF4 nanocrystals where lanthanide activators reside, which induces great enhancement of optical performance of nanostructured glass ceramics. Under 980 nm near-infrared laser excitation, multi-color upconversion luminescence tuning from green to yellow and finally to red was easily realized by simply modifying Lu/Yb ratio in the glass ceramics containing Er3+: NaLu1−xYbxF4 (x = 0 ∼ 1) nanocrystals. It is expected that such glass self-crystallization strategy may offer a great opportunity to design and develop other new transparent nano-composites with a wide range of tunable optical properties.