Preparation of PbF2:Ho3+, Er3+, Yb3+ phosphors and its multi-wavelength sensitive upconversion luminescence mechanism

In this paper, PbF2:Ho3+, Er3+, Yb3+ phosphors are prepared by a high-temperature solid-state method. The crystal structure acquired by X ray powder diffractometer shows that the resultant phosphor is a pure cubic PbF2 crystal. The upconversion (UC) emission spectra of samples are performed by a fluorescence spectrophotometer coupled with lasers of 980 nm, 1064 nm and 1550 nm, presenting the green emission in the range of 541 similar to 548 nm and red emission in the range of 653 similar to 667 nm, corresponding to the excitation path: Ho3+: F-4(9)/2 -> I-4(15/2), Er3+:S- 4(3)/2 -> I-4(1)5/(2) Er3+ :F-4(9/)2 -> I-4(1)5/(2) and Ho3+: F-5(5)-> I-5(8). Finally, the UC luminescence mechanism is analyzed under excitation of different wavelengths. The result shows that the phosphors have a promising prospect for application in anti-counterfeiting technologies and solar cell field.