Fig. 3: Energy dispersive spectroscopy maps showing the yttrium and ytterbium distribution after growing homogeneous α-NaYF4 (top row) and heterogeneous CaF2 (bottom row) shell domains on optically active α-NaYF4:Yb:Er core nanocrystals (NCs). | Nature Communications

Fig. 3: Energy dispersive spectroscopy maps showing the yttrium and ytterbium distribution after growing homogeneous α-NaYF4 (top row) and heterogeneous CaF2 (bottom row) shell domains on optically active α-NaYF4:Yb:Er core nanocrystals (NCs).

From: Preventing cation intermixing enables 50% quantum yield in sub-15 nm short-wave infrared-emitting rare-earth based core-shell nanocrystals

Fig. 3

Representative low magnification high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images (a, b), yttrium chemical maps (c, d), ytterbium chemical maps (e, f), and overlay composites between the Yb/Y (g) or Yb/Ca (h) chemical maps.

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