Synthesis and the luminescent properties of the Nd3+ ions doped three kinds of fluoride nanocrystals in organic solvents

Abstract Oleic acid (OA)-modified LaF 3 :Nd, NaYF 4 :Nd and CaF 2 :Nd nanocrystals (NCs) with the different Nd 3+ ion concentration (2% and 5%) have been prepared. The structure and morphology of NCs were identified by XRD, TEM, FT-IR and TGA. The size of OA-modified NC is a mean diameter of 5–10 nm and can be dispersed in common organic solvents to form a transparent solution. The optical loss of NCs in organic solvent is the first time to discuss in this work. The luminescence properties of NCs were also characterized and studied by fluorescence spectrometer. The nanoparticles in solid and in the solution all exhibited the strong emission at the 1060 nm when the materials were excited around 800 nm. Compared with the LaF 3 and CaF 2 matrix, NaYF 4 as the host can protect the Nd 3+ ions more efficiently away from the nonradiative transitions. The longest luminescent lifetime of the solid NaYF 4 :2%Nd NCs was up to 136 μs, and the little difference of the fluorescence lifetime existed between the NCs in solid state and in solution. The low optical loss in organic solvent indicated that the Nd 3+ ions-doped fluoride NCs are promising materials for optical amplification fields.