Figure 3From: Synthesis of NaYF4:Yb3+, Er3+ upconversion nanoparticles in normal microemulsions Colloidal solutions of NaYF 4 :20% Yb 3+ , 2% Er 3+ sample in n -hexane. (A) The solution showing its transparency. (B) Visible upconversion luminescence excited by 980 nm laser oxide. (C) Upconversion luminescence emission spectrum.Back to article page