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

Figure 6

Emission spectra of the pure crystals of (a): CsY₂F₇: 78% Y, 20% Yb, 2.0% Er nanocrystals generated in HEEDA, (b) : CsY₂F₇∶ 78%  Y, 20%  Yb, 2.0%  Er nanocrystals generated in the microwave synthesis apparatus. (c): CsY₂F₇ :78%  Y, 20%  Yb, 2.0%  Er nanocrystals generated in HEEDA and heat treated for 45 minutes at 600^∘C, (d): Hexagonal bulk NaYF₄: 18%  Yb³⁺, 2.0%Er³⁺.