Abstract: Three organic-inorganic hybrid phosphors were synthesized by a surface coordination method with SrAl₂O₄:Eu²⁺, Dy³⁺ powder and maleic anhydride,oleic acid and 2,2’dipyrical ligand respectively, and characterized by means of IR, SEM, XRD, fluorescent spectra and water resistance experiments. The results show that Sr²⁺²⁺ on the surface of SrAl₂O₄:Eu²⁺, Dy³⁺ phosphor is coordinated with O and N atoms of maleic anhydride and oleic acid and 2,2’dipyrical ligand respectively. The crystal structures, the shapes and positions of excitation and emission peak of coated phosphors are the same as that of uncoated phosphors, but after coordination encapsulation, the relative luminous intensity and the afterglow life are decreased, and the roughness of crystal structure is increased, and the stability in water is improved. The best ligand is maleic anhydride. The luminous intensity and afterglow life of the phosphors coordinated with maleic anhydride are less 3％ and 5％ respectively than that of the uncoated phosphors.

Key words: phosphor, ligand, encapsulation, organic-inorganic hybrid