TONG Yifan, DAI Yingcai, YU Yongli
(School of Science, Northeastern University, Shenyang 110819, Liaoning, China)
Abstract: Non-rare earth ion-doped NaLuF4:Yb,Ho nanoparticles (NaLuF4:Yb,Ho NPs) were synthesized by using a solvothermal method. The effects of the types of doping ions (Al3+, Mg2+, Ca2+, Sr2+ and Ba2+) and the doping concentration on luminescence properties of the NaLuF4:Yb,Ho NPs were systematically studied. The doping of Al3+, Mg2+ and Ca2+ could increase the luminescence intensity of the nanoparticles, while the corresponding maximum luminescence intensities of the products were 3.9 times, 3.8 times and 3.3 times that of the undoped nanoparticles, respectively. When Sr2+ and Ba2+ were used separately, the luminescence intensity of the nanoparticles was decreased. XRD results indicated that the doping of Al3+ and Mg2+ could induce the transition of NaLuF4 crystals from tetragonal to hexagonal phase, while the crystal phase transition was an important reason for the increase of the luminescence intensity. Ba2+ doping caused the formation of non-NaLuF4 crystals in the products. TEM results revealed that the particle size of the NaLuF4:Yb,Ho NPs doped with Al3+ was significantly small, in the range of 30-60 nm.
Key words: upconversion luminescence; doping; nanoparticles; NaLuF4