Enormously enhanced upconversion emission in β-NaYF4:20Yb,2Er microcrystals via Na+ ion exchange

• Published in: Journal of materials science Vol. 52; no. 2; pp. 869 - 877
• Main Authors: Fan, Shaohua, Wang, Shikai, Xu, Wenbin, Li, Meng, Sun, Hongtao, Hu, Lili
• Format: Journal Article
• Language: English
• Published: New York Springer US 2017; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Crystal structure; Crystallography and Scattering Methods; Efficiency; Emission; Fluorides; Ion exchange; Lasers; Materials Science; Microcrystals; Optics; Original Paper; Polymer Sciences; Sodium compounds; Solid Mechanics; Solid state lasers; Upconversion; Body Defect; Efficient Upconversion; GdF3; Trisodium Citrate Dihydrate; Upconversion Emission
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-016-0382-x

Efficient upconversion (UC) microcrystals are important for the development of novel photonic markers, solid-state lasers, displays, etc. Herein, we report on greatly enhanced UC emission in β-NaYF 4 :20Yb,2Er microcrystals via a simple ion-exchange reaction. The ion exchange accompanying with an ionic redistribution process is demonstrated. By simply controlling the amount of NaF (0–8.0 mmol), reaction temperature (140–220 °C), and duration (0–144 h), enormous enhancement of the UC emission up to ~4200 times is obtained compared with the pre-synthesized β-NaYF 4 :20Yb,2Er microcrystals. The decrease of body defects and change of local structure around lanthanide may account for the UC emission enhancement. This method may apply to other UC materials to increase the UC emission efficiency.