Structure, enhancement and white luminescence of multifunctional Lu6O5F8:20%Yb3+,1%Er3+(Tm3+) nanoparticlesvia further doping with Li+ under different excitation sources

Abstract

A series of Lu₆O₅F₈:20%Yb³⁺,1%Er³⁺(Tm³⁺),x%Li⁺ (0 ≤ x ≤ 12) nanoparticles with average size from 20 to 320 nm upon increasing Li⁺ concentration were prepared by a coprecipitation method. The detailed crystal structure of Lu₆O₅F₈ as a new matrix is firstly analysed via retrieved refinement of the powder X-ray diffraction (XRD). In addition, the corresponding Powder Diffraction File card information was also obtained through indexing the XRD pattern of the host. Upconversion under excitation at 980 nm, downconversion with Xe lamp as excitation source and cathodoluminescence properties of Lu₆O₅F₈:20%Yb³⁺,1%Er³⁺(Tm³⁺),x%Li⁺ (0 ≤ x ≤ 12) nanoparticles were compared and studied. It is worthwhile pointing out that according to the effects of Li⁺ on emission intensity ratio, white UC emission was achieved in the Lu₆O₅F₈:6%Yb³⁺,0.3%Er³⁺,0.4%Tm³⁺,5%Li⁺ compared to Li⁺ free sample with the same activator concentration. The reasons behind this behavior were presented and discussed. All in all, Li⁺ ion would be a wonderful luminescence intensifier for lanthanide ions, and the multifunctional lanthanide ion-doped Lu₆O₅F₈ nanoparticles have potential application in photoluminescence areas and field emission display devices.