ZHAO Jun-wei, SHAN Han, JIA Tie-kun, FAN Yi, KONG Xiang-gui. Effect of High Temperature Annealing in Nitrogen on Upconversion Luminescence of NaYF<sub>4</sub>∶Yb<sup>3+</sup>, Er<sup>3+</sup> Nanoparticles[J]. Chinese Journal of Luminescence, 2011,32(12): 1227-1232
ZHAO Jun-wei, SHAN Han, JIA Tie-kun, FAN Yi, KONG Xiang-gui. Effect of High Temperature Annealing in Nitrogen on Upconversion Luminescence of NaYF<sub>4</sub>∶Yb<sup>3+</sup>, Er<sup>3+</sup> Nanoparticles[J]. Chinese Journal of Luminescence, 2011,32(12): 1227-1232DOI:
Effect of High Temperature Annealing in Nitrogen on Upconversion Luminescence of NaYF4∶Yb3+, Er3+ Nanoparticles
nanoparticles with the size about 40 nm were successfully prepared by the combination of coprecipitation and hydrothermal methods using trisodium citrate as chelator. The obtained sample was divided into two parts
one of them was annealed in nitrogen at 300 ℃ for 2 h. The crystal structure of the NaYF
4
∶Yb
3+
Er
3+
nanoparticles before and after annealing treatment are in cubic phase
the size of which is about 40 nm. Under the excitation of 980 nm laser
the total upconversion luminescence intensity and the relative green emission intensity of the sample after annealing is much stronger than that of the sample without annealing treatment. It is found that high temperature annealing improved the crystallization of the sample and reduced the concentration of the organic molecules on the surface of the nanoparticles
resulting in a great improve of the upconversion luminescence property.
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