Upconversion luminescence in sub-10 nm β-NaGdF₄:Yb³⁺,Er³⁺ nanoparticles: an improved synthesis in anhydrous ionic liquids.

ABSTRACT: Sub-10 nm β-NaGdF₄:18% Yb³⁺,2% Er³⁺ nanoparticles were synthesized in ethylene glycol and various ionic liquids under microwave heating. The products were characterized by powder X-ray diffraction, electron microscopy, and upconversion (UC) luminescence spectroscopy. After Yb³⁺ excitation at 970 nm, Er³⁺ ions are excited by energy transfer upconversion and show the typical green and red emission bands. The UC luminescence intensity was optimized with respect to reactant concentrations, solvents, and reaction temperature and time. The strongest UC emission was achieved for sub-20 nm core-shell nanoparticles which were obtained in the ionic liquid diallyldimethylammonium bis(trifluoromethanesulfonyl)amide from a two-step synthesis withou

SUBMITTER: Tessitore G 

PROVIDER: S-EPMC9074172 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature