Enhanced luminescence of CaF₂ :Er³⁺ /Nd³⁺ nanoparticles coated by fluorinated β-diketone

In this study, several CaF₂ nanoparticles doped with individual ions Nd³⁺ and Er³⁺ were synthesized with ligands pentafluorobenzoyl trifluoroacetone (PBTA) and 2-naphthoyltrifluoroacetone (NTA), which served as modifiers. Influence of the modifiers on the luminescence properties of the nanoparticles was investigated. The as-prepared nanoparticles had a similar size and dispersion with an irregular spherical shape, which reduced the influence of particle size on the luminescence of the nanoparticles. The luminescence spectra of these nanoparticles showed the characteristic luminescence of the central lanthanide ions under excitation of the maximum excitation wavelength. Compared with nanoparticles modified by the NTA ligand, nanoparticles modified by the PBTA ligand possessed stronger luminescence intensity for the doping Nd³⁺ or Er³⁺ ions.