Facile synthesis and luminescence properties of highly uniform YF3:Ln3+ (Ln=Eu, Tb, Ce, Dy) nanocrystals in ionic liquids

Uniform YF 3 nanocrystals were prepared through a facile ethylene glycol (EG)/ionic liquid interfacial synthesis route in a imidazolium ionic liquids (1-octyl-3-methylimidazolium hexafluorophosphate) with the ionic liquids acting as both reagents and templates. The partial hydrolysis of PF 6 − was utilized to introduce a fluoride source. X-ray diffraction (XRD), field emission scanning microscopy (FE-SEM) and transmission electron microscopy (TEM) have been used to study the morphologies and crystal structure. The detailed growth mechanism of the YF 3 nanocrystals was researched. Furthermore, under ultraviolet exaltation, the phosphor of YF 3 :Eu 3+ and YF 3 :Tb 3+ shows red and green emission, corresponding to 5 D 0 – 7 F 1 transition of Eu 3+ and 5 D 4 – 7 F 5 transition of Tb 3+ . The emission spectrum of YF 3 :Ce 3+ phosphor exhibits one dissymmetrical band extending from 350 to 500 nm with a maximum at about 383 nm. A bright fluorescent yellow emission at 574 nm and blue emission at 487 nm were observed in the YF 3 :Dy 3+ . These novel nanocrystals could be potentially used in biolabels and light emitting diodes (LEDs).