Efficient fluorescence of dissolved CaF2:Tb3+ and CaF2:Ce3+, Tb3+ nanoparticles through surface coating sensitization

Oleic acid (OA)-modified CaF2:Tb3+ nanoparticles with various Tb3+ concentrations and CaF2:Ce3+, Tb3+ nanoparticles were synthesized. The as-prepared nanoparticles were shown to be well dissolved in some common organic solvents, such as chloroform and toluene. The nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD) and transmission electron microscopy (TEM). The investigation of fluorescence properties of CaF2:Tb3+ nanoparticles showed that the Tb3+ ions could be sensitized efficiently by the surface coating of OA and CaF2:Tb3+ nanoparticles with 10 mol% Tb3+ concentrations possess the highest emission intensity. The comparison of emission for CaF2:Ce3+, Tb3+ and CaF2:Tb3+ (10 mol%) nanoparticles revealed that the emission intensity of the former is about 4.5 times as strong as that of the latter.