The effect of alkali metal ions on crystallization characteristics and luminescent properties of transparent Er3+-doped fluorosilicate glass-ceramics

In current work, transparent fluorosilicate glass-ceramics (GCs) containing NaYF4:Er3+ nanocrystals were successfully prepared by controlled heat treatment process. The thermal properties and crystallization characteristic temperatures were determined by the differential scanning calorimetry (DSC). The X-ray diffraction (XRD) and transmission electron microscope (TEM) were used to confirm the formation of NaYF4 nanocrystals in glass matrix. Energy dispersive spectrometer (EDS) results and Judd-Ofelt (J-O) parameters analysis demonstrated the incorporation of Er3+ into NaYF4 nanocrystals. Intense 2.7 μm luminescence was observed in Er3+-doped GCs upon excitation with a 980 nm laser diode (LD). Furthermore, the effect of different alkali metals (Li+, Na+, K+) on crystallization characteristics and luminescent properties has been studied in detail, which indicates Li+ is the most favorable option for mid-infrared luminescence properties compared with Na+ and K+. The excellent spectroscopic characteristics suggest that the obtained GCs may be promising materials for mid-infrared fiber lasers.