Research Article

Hydrothermal Synthesis of β-NaYF4:Yb, Er Nanocrystals with Upconversion Fluorescence Using Tetraethylene Pentamine as Chelating Ligand

Figure 9

FE-SEM images of NaYF4:Yb, Er nanocrystals prepared under different solvent composition: (a) water/ethanol = 2 : 1; (b) water/ethanol = 1 : 1; (c) water/ethanol = 1 : 2 (RE/TEPA = 1 : 1; 𝑡 = 6 h; 16.7 mmol/L).
369605.fig.009a
(a)
369605.fig.009b
(b)
369605.fig.009c
(c)