Controlled synthesis of NaYF4 nanoparticles and upconversion properties of NaYF4:Yb, Er (Tm)/FC transparent nanocomposite thin films

► β-NaYF4:Yb, Er (Tm) nanoparticles as excellent upconverting powder. ► The upconverting nanoparticles disperse well in FC resin. ► FC nanocomposites offer luminescence, high transparency, and stain resistance. ► β-NaYF4:Yb, Er (Tm)/FC nanocomposites show intense green (blue) luminescence.