Upconversion Luminescence Properties of YF3:Yb3+, Er3+ Nanoclusters

The synthesis, characterization, and spectroscopy of upconverting Yb3+/Er3+ codoped YF3 rod-like nanoclusters are presented. The YF3 nanoclusters were synthesized by a simple hydrothermal method. The clusters structure was characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Under 978 nm laser excitation, stronger blue (F-4(5/2) -> I-4(15/2) and P-2(3/2) -> I-4(11/2)) and green (S-4(3/2), H-2(11)/(2) -> I-4(15/2)) upconversion luminescence were observed at 978 nm. The measured intensity of upconversion luminescence was different when pump power changed, which shows that the blue and green upconversion luminescence come from three-photon and two-photon energy transfer processes, respectively.