Microcrystalline Anti-Stokes Luminophores NaYF4 Doped with Ytterbium, Erbium, and Lutetium Ions

Microcrystalline anti-Stokes luminophores NaY1–x–y–zYbxEryLuzF4 were obtained for the first time by hydrothermal synthesis. These compounds crystallize in the hexagonal crystal system, structural type β-NaYF4. It was found that the addition of a non-luminescent lutetium(III) ions results in up-conversion luminescence enhancement in more than 2 times upon 980 nm excitation.