Controlled synthesis and luminance properties of lanthanide-doped β-NaYF4 microcrystals

Abstract Hexagonal Yb 3+ ,Er 3+ -doped NaYF 4 crystals with different morphologies were synthesized by a facile hydrothermal method at 140–200 °C. Their shape and size could be controlled by varying hydrothermal temperature, time and doping effect of Ce 3+ ions. Interestingly, the products displayed hexagonal sheet, plate, crown-like prism to tube changes in the temperature range from 140 to 200 °C. A combination of “diffusion-controlled growth” and “selective adsorption” was proposed to understand the formation of the NaYF 4 crystals with well-defined shapes. NaYF 4 :Yb 3+ /Er 3+ crystals exhibited shape-dependent up-conversion (UC) luminescence under excitation of 980 nm, and their luminescence property could be tuned by doping Ce 3+ ions.