Synthesis and luminescence properties of YF3:Ce3+/Tb3+ nanocrystals.

YF3:Ce3+, YF3:Tb3+, and YF3:Ce3+/Tb3+ nanocrystals were synthesized by an ethylenediaminetetraacetic acid (EDTA)-assisted hydrothermal method and characterized by X-ray diffraction and scanning electron microscope. In the excitation spectra, there is one broad excitation band at 285 nm for YF3:Ce3+ and 255 nm for YF3:Tb3+, which are related to the f-d excitations of the Ce3+ and Tb3+ in the host, respectively. In the emission spectra of YF3:Ce3+/Tb3+ nanocrystals under different excitation wavelengths (285 and 255 nm), both spectra exhibit the emissions of Ce3+ and Tb3+, indicating that energy transfer could take place not only from Ce3+ to Tb3+ but also from Tb3+ to Ce3+ ions.