Synthesis and Characterization of Upconversion Fluorescent Yb^𝟑+, Er^𝟑+ Doped CsY_𝟐F_𝟕 Nano- and Microcrystals

Figure 7

Double logarithmic plots of the emitted light intensity versus the power density of the exciting light for pure crystals of (a): CsY₂F₇∶ 78%  Y, 20%  Yb, 2.0%  Er generated in HEEDA, (b): CsY₂F₇∶ 78%  Y, 20%  Yb, 2.0%  Er generated in the microwave synthesis apparatus. (c) : CsY₂F₇∶ 78%  Y, 20%  Yb, 2.0%  Er generated in HEEDA and heat treated for 45 minutes at 600^∘C, (d): Hexagonal bulk NaYF₄∶ 18%  Yb³⁺, 2%  Er³⁺.