Upconversion emission of SrYbF5:Er3+ nanosheets modified by Tm3+ ions

Through a hydrothermal route, the Er3+ and Tm3+ co-doped SrYbF5 nanosheets were synthesized. The resulting samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and luminescence spectra. Under the excitation of 980 nm laser irradiation, the upconversion emissions of Tm3+ ions centered at 474 nm (1G4→3H6), 679 nm (3F2→3H6), 699 nm (3F3→3H6), 803 nm (3H4→3H6) and emissions of Er3+ ions centered at 522 nm (2H11/2→4I15/2), 543 nm (4S3/2→ 4I15/2), 654 nm (4F9/2→4I15/2) were observed. The upconversion emissions of Er3+ ions were adjusted by the concentration of Tm3+ ions. The energy transfer mechanisms among Er3+-Yb3+-Tm3+ in SrYbF5 nanosheets were discussed.