Controlled synthesis of YF3 nanocrystals with multiple morphologies in ethylene glycol

YF3 is an important host matrix for lanthanides doping to give both strong down- and up-conversion luminescence with high quantum efficiency. Controlled synthesis of YF3 nanocrystals is an efficient route to obtain different YF3 nanocrystals satisfying for different applications and controlling their fluorescence. Here we present a facile approach to selectively synthesize different YF3 nanocrystals using ethylene glycol (EG) as solvent. Five distinct morphologies can be conveniently obtained through changing the fluoride sources and chelating ligands in the EG solution. The prepared products were characterized and their formation mechanisms were proposed. After doped with different lanthanides, these samples can give both down- and up-conversion luminescence, suggesting that they are good nanoparticulate hosts. A comparison of fluorescent intensities between different products has been made, offering us an opportunity to study the relationship between fluorescence intensities and morphologies of YF3 nanostructures. Our results suggest that formation of assemblies is a feasible way to enhance the fluorescence of lanthanide nanocrystals in addition to the size control.

► Shape-control synthesis of YF3 nanocrystals is achieved by selecting ethylene glycol as solvent.
► Different YF3 nanostructures can be synthesized by changing fluoride sources and chelating ligands.
► Formation mechanism responsible for five different YF3 nanostructures is proposed.
► Down- and up-conversion photoluminescence can be realized from these YF3 nanostructures after lanthanide doping.
► Relationship between fluorescent intensities and morphologies of YF3 nanostructures is studied.