Abstract: The luminophors of silicate (Li, Ca, Gd) SiO₃:Eu, Bi were sythesised and luminescence properties of Bi³⁺, Eu³⁺, and Gd³⁺ ions were studied. The effects and regularities of Gd³⁺ ion on the luminescence of Eu³⁺ and Bi³⁺ ions were investigated. The study on the luminescence of silicates (Li, Ca, Gd) SiO₃:Eu, Bi shows that there are energy transitions from Bi³⁺ ion to Eu³⁺ ion and that Bi³⁺ ions act as both sensitizers and co-activators and that the spectral energy distribution of the luminophors depends on the Gd³⁺ ion content. It is shown that Gd³⁺ ion can greatly promote the sensitive effect of Bi³⁺ on Eu³⁺ and turn the main emission of Eu³⁺ ion from ⁵D₀-⁷F₁ to ⁵D₀-⁷F₂ transition as the condensations of Gd³⁺ ion increase.
Under UV excitation of 393 nm, the luminescence intensities of Eu³⁺ in Li_0.3Ca_0.4Gd_0.268SiO₃Eu_0.025Bi_0.007 are the same as or more than those of Y(V, P)O₄:Eu for either ⁵D₀-⁷F₁ or ⁵D₀-⁷F₂ transition emission. The experiment results show that the optimum synthesis conditions are 950℃ and 4hrs fired twice for Li_0.30 Ca_0.40 Gd_0.30SiO₃:Eu, Bi and that silicate Li_0.30 Ca_0.40 Gd_0.30 SiO₃ is an excellent host lattice to obtain efficient photoluminescent materials.