Controlled Synthesis And Luminescent Properties Of Ca0.80yb0.20f2.2: 0.2 % Tm3+ Nanocrystals

In this paper, a series of high quality Ca0.80Yb0.20F2.2: 0.2 % Tm3+ nanocrystals (NCs) with size range from 3.2 nm similar to 18.6 nm were obtained via solvothermal method by changing reaction conditions. The effect of solvent system, fluorine source, reaction temperature, ratio of F-/Ca(CF3COO)(2) and reaction time on the growth of NCs were investigated systematically by X-ray diffraction (XRD), transmission electron microscope (TEM) and high-resolution transmission electron microscope (HRTEM). It was founded that solvent system and fluorine source has a more prominent influence on the growth of NCs compared with the other parameters. Besides, upconversion luminescent (UCL) properties and luminescence lifetime (tau) of (1)G(4) excited state of Tm3+ for the synthesized NCs were studied. Long decay lifetime of 1.15 ms with pulse laser excitation at 980 nm was found. This method can be used to prepare other NCs with high luminescence efficiency which can be further used for biomedical applications.