Effect of glass network modifier R2O(R=Li, Na and K) on upconversion luminescence in Er3+/Yb3+ co-doped NaYF4 oxyfluoride glass-ceramics

The effect of glass network modifier R2O(R=Li, Na, K) on upconversion luminescence in Er3+/Yb3+ co-doped Na YF4 oxyfluoride glass-ceramics was investigated. NaY F4 nanocrystals with different sizes were studied under glass network modifier alkali mental oxide. The nanocrystals size in NaY F4 of Li2 O modified samples was 11 nm, whereas in the Na2 O and K2 O modified sample, the crystal size was 25 and 43 nm, respectively. It was found that red, yellow and green upconversions were observed in SAL, SAN, SAK glass ceramics. The reported results would deepen the understanding of size effects on the lanthanide upconversion in nanocrystals.