Phase-tunable synthesis and upconversion photoluminescence of rare-earth-doped sodium scandium fluoride nanocrystals

Abstract

Monodisperse rare-earth-doped Na_xScF_3+x nanocrystals have been synthesized via the co-thermolysis of trifluoroacetates. They can be easily tuned from monoclinic-phase (Na₃ScF₆) to hexagonal-phase (NaScF₄) just through changing the ratio of Na(CF₃COO) to Sc(CF₃COO)₃. The obtained samples show bright upconversion photoluminescence. Furthermore, luminescence with a wide spectrum of colors, including white, has been achieved by the appropriate blend of NaScF₄:Yb³⁺/Er³⁺ and NaScF₄:Yb³⁺/Tm³⁺ nanocrystals.