Preparation And Luminescence Properties Of Rare Earth Ions Doped NaYF₄

In this paper, ytterbium (Yb3+)-erbium (Er3+) ions codoped NaYF4 and ytterbium (Yb3+)-Thulium (Tm3+) ions codoped NaYF4 were synthesized by precipitation method, the effect on the upconversion luminescence of the main preparation conditions was investigated, and the upconversion mechanism was analyzed. The results show that:Hexagonal NaYF4 Yb, Er up-conversion materials with excellent green luminescence can be obtained when the concentration of Yb3+and Er3+were 15%mol,3%mol respectively, roasted in the air for 3 h at 600℃, the main up-conversion approach is the energy transfer between Yb3+and Er3+, the emission of Er3+at 527 nm,539 nm and 653 nm corresponding to the transition between 2H11/2→4I15/2,4S3/2→4I15/2,4F9/2→4I15/2, and the red, green emission of Er3+ are two-photon process.Hexagonal NaYF: Yb, Tm up-conversion materials with blue luminescence can be obtained when the concentration of Yb3+and Tm3+were 60%mol,0.4%mol respectively, roasted in the air for 2 h at 600℃. There are three diatinct emission band under 980 nm near-infrared excitation, weak violet band near 449 nm, strong blue band near 475 nm, weak red band near 644 nm, corresponding to the transition between 1D2→3F4,1G4→3H6,1G4→3F4 of Tm3+, and the emissions are three-photon process.