Abstract: M₂B₅O₉X∶Re(M=Ca, Sr, Ba; X=Cl, Br; Re=Eu, Tb) phosphors were synthesized via solid state method. The products were characterized with X-ray powder diffraction and luminescence spectrometer. The luminescent properties as well as the influences of the matrix composition and other doping ions on the luminescence of the rare earth ions of the co-doped phosphors were investigated. The coexistence of Eu³⁺, Eu²⁺and Tb³⁺ were observed in these matrices. The phenomenon may be explained by the electron transfer theory. The sensitization of Ce³⁺ ion improves the intensity of emission of Eu²⁺ and Tb³⁺. The competition between electron transfer among conjugate rare earth ions and energy migration might be the reasons for the observation. We predict a novel trichromatic phosphor co-doped with Eu³⁺-Tb³⁺ in M₂B₅O₉X.

Key words: Solid state synthesis at high temperature, Luminescence character, Electronic transport, Energy migration