Synthesis and upconversion properties of Ln3+ doped YOF nanofibers

Nanofibers of YOF doped with trivalent lanthanide ions (Ln3+) have been synthesized successfully via an electrospinning method combining with high-temperature calcination in air. Scanning electron microscopy (SEM) observations showed that the nanofibers had uniform one-dimensional (1D) morphology. X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) images revealed that the calcined fibers were constituted by rhombohedral phase yttrium oxyfluoride nanocrystals. Under the excitation from a 980 nm laser diode, YOF:Yb3+,Tm3+ and YOF:Yb3+,Er3+ fibers emitted blue and red light, respectively. Upconversion mechanisms of these YOF:Ln3+ fibers were also discussed in detail.

Graphical abstractLn3+ doped oxyfluoride nanofibers were fabricated successfully by using electrospinning method combining with high-temperature calcination in air. Firstly, we prepared RE(CF3COO)3/PVP composite fibers by typical electrospinning. Then, the composite fibers were sintered at 600 °C in air. The annealed sample presented 1D morphology. The calcined nanofibers were polycrystalline and were densely packed by nanocrystals. Under the excitation of 980 nm laser, YOF:Yb3+,Tm3+ and YOF:Yb3+,Er3+ nanofibers gave off blue and red upconversion fluorescence, respectively.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► YOF nanofibers have been prepared via electrospinning. ► The calcinated fibers keep morphology of fiber and are packed with fine grains. ► With the excitation from 980 nm, YOF:Yb3+,Tm3+ and YOF:Yb3+,Er3+ nanofibers emit blue and red upconversion fluorescence, respectively.