Synthesis of monoclinic Na3ScF6:1 mol% Er3+/2 mol% Yb3+ microcrystals by a facile hydrothermal approach

For the first time, a facile hydrothermal approach to synthesize the highly efficient 1 mol% Er3+/2 mol% Yb3+ codoped Na3ScF6 upconversion (UC) microcrystals is reported. The X-ray diffraction (XRD) patterns indicate that the prepared powders possess monoclinic structure. Field emission scanning electron microscopy (FESEM) shows that these samples have monocline morphology with high crystallinity. Under 980 nm diode laser excitation, Na3ScF6:1 mol% Er3+, 2 mol% Yb3+ microcrystals emit strong green and red upconversion emissions. UC mechanisms for these emissions are proposed based on their pump power dependences.

► For the first time, the highly efficient Er3+/Yb3+ codoped Na3ScF6 upconversion (UC) microcrystals were successfully synthesized via a facile hydrothermal route.
► Na3ScF6:1Er3+/2Yb3+ samples emitted strong green and weak red upconversion emissions under diode laser excitation of 980 nm.
► The mechanisms of intense green UC emissions in Na3ScF6:1Er3+/2Yb3+ samples are proposed in detail.