Novel trichromatic phosphor Co-doped with Eu, Tb in SiO₂ gel matrix

The Eu, Tb co-doped SiO₂ matrix tricolor fluorescence system was prepared by sol-gel technique. Red emission at 618 nm, green emission at 543 nm and blue emission at 350-500 nm were observed in the PL spectra of the sample, indicating that Eu³⁺, Eu²⁺ and Tb³⁺ ions coexisted in the matrix. In the co-doped sample, the blue emission of Eu ²⁺ was much stronger than that of the sample single doped with Eu, which implied that the electron transfer between Eu³⁺ and Tb ³⁺ maybe happened in the SiO₂ matrix. The influences of the annealing temperature and Tb concentration on the PL spectra of the samples were investigated. The optimal doped concentration of Tb was determined to be 0.2% and the optimal annealing temperature 850°C. Annealed at 600°C, Tb³⁺ had a sensitizing effect on Eu³⁺ in the SiO ₂ matrix, and the emission intensity of Eu³⁺ in the Eu, Tb co-doped sample was more than four times that of the single doped sample, which could be attributed to the energy transfer from Tb³⁺ to Eu ³⁺.