Preparation and Characterization of Up-Conversion Nanocrystal NaYF4 Co-Doped with Rare-Earth Ions

Preparation and Characterization of Up-Conversion Nanocrystal NaYF4 Co-Doped with Rare-Earth Ions
　　Up-conversion luminescence nanocrystal NaYF4 co-doped with rare-earth ions was prepared by hydrothermal method in the prescence of complexing agent EDTA. The optimum composition of four types of samples were discussed respectively, and optimally annealing temperature was determined. The ability of agent EDTA controlling the particle size was also neodymium magnets discussed.The phase, structure and surface topography were analysised by X-ray diffraction, transmission electron microscope and scansion electron microscope. The results showed that hexagonal nanocrystal NaYF4 was prepared by hydrothermal method. The up-conversion spectrum was measured by Hitachi F-4500 spectrophotometer, under 980 nm diode laser excitation. The impact of different concentration of rare-earth ions on the up-conversion luminescence intensity was discussed. The relationship between up-conversion relative intensity and pump power was also studied. Ground state absorption, http://www.chinamagnets.biz/ excitation state absorption and energy transfer were used in discusing the up-conversion mechanism of the nanocrystal and the pertinent up-conversion mechnism models of the nanocrystal were proposed. 更多还原