Photoluminescence Properties Of R3 +: CaF2 (R = Er, Yb, Dy) Nanoparticles And Yb3 + Single-doped Phosphate Glass

The materials doped rare earth not only play an significant role for the application on agriculture, military, environment, health care, energy source, and so on, but also be used in lighting facility, lighting for temperature sensor, laser and other optical component.Er³⁺-doped, Yb³⁺-doped, Er³⁺/Yb³⁺co-doped and Er³⁺/Yb³⁺/Dy³⁺co-doped CaF₂ nanoparticles have been prepared by high-temperature solid phase sintering method at this paper. Crystal structure, surface appearance and energy level structure of samples were represented by X-ray diffraction（XRD）, scanning electron microscope（SEM） and spectrophotometer. The results showed that CaF₂ host was a typical cubic fluorite structure and the crystal structure of CaF₂ was affected, when doped with rare earth, especially Yb³⁺-doped intensely. At the same time, Yb³⁺-doped phosphate glasses have also been prepared and the concentration of Yb³⁺-doped samples was 0, 5, 11, 13, 20 mol% by the similar method.The up-conversion photoluminescence spectra of Er³⁺-doped, Yb³⁺-doped, Er³⁺/Yb³⁺ co-doped CaF₂ nanoparticles have been measured under 980 nm pump light and three emission peaks were observed at 478（blue）, 540（green） and 659 nm（red） respectively corresponding to the 4F7/2→4I15/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of Er³⁺ ions. When the concentration of Er³⁺/Yb³⁺co-doped CaF₂ nanoparticles was 1.5:10, the intensity of photoluminescence spectra was optimal.The absorption spectra of Yb³⁺/Dy³⁺ co-doped, Er³⁺/Dy³⁺ co-doped and Er³⁺/Yb³⁺/Dy³⁺ co-doped CaF₂ nanoparticles indicate that Dy³⁺ ions ability of absorption was weak in the CaF₂ host.The absorption of Yb³⁺ ions was intense in 870-1000 nm and many absorption peaks of Er³⁺ ions was found in the visible range. The emission spectra of samples revealed that two emission peaks were observed at 546( Er³⁺: 4S3/2→4I15/2) and 588 nm( Dy³⁺: 4F9/2→6H13/2) under 376 nm excitation.Yb³⁺-doped phosphate glasses was measured by 325 nm helium cadmium laser and the blue（490 nm） and near-infrared（1008 nm） light were obtained. The Yb³⁺-doped optimal concentration of 1008 nm near-infrared photoluminescence emission was 13 mol%.