A Room-Temperature Strategy to Synthesize Ce/Tb-Codoped NaYF 4 Nanoparticles with a Photoluminescence Quantum Yield Exceeding 50.

NaYF 4 :Ce 3+ ,Tb 3+ down-conversion nanoparticles with a photoluminescence quantum yield (PLQY) of 54.8% are synthesized by using a ligand-assisted coprecipitation method in this study. The reaction is completed within 1 min at room temperature, and short-chain hexanoic acid and hexylamine serve as the binary ligands, which enable us to synthesize highly luminescent NaYF 4 :Ce 3+ ,Tb 3+ nanoparticles at room temperature. X-ray diffraction (XRD) and transmission electron microscopy (TEM) are used to characterize the as-prepared nanocrystals. The results reveal that the NaYF 4 :Ce 3+ ,Tb 3+ nanocrystals exhibit excellent dispersion and have a particle size of 2.7 nm. Our NaYF 4 :Ce 3+ ,Tb 3+ nanocrystals possess the advantages of room-temperature preparation, high PLQY, and ultrasmall particle size. These results reveal that the NaYF 4 :Ce 3+ ,Tb 3+ nanocrystals might have a high potential in the applications of lighting, display devices, and bioimaging.