Synthesis and multi-color tunable luminescence performance of Tb3+/Eu3+ co-doped SrGdGa3O7 phosphors

Some Tb³⁺/Eu³⁺ doped SrGdGa₃O₇ (SGGO) phosphors were fabricated, achieving multi-color tunability through the addition of a sensitizer. The experimental results indicate that the doped ions are uniformly distributed, with no impurity phases detected. In SGGO-based phosphors, Eu³⁺ ions serve as activators and exhibit an optimal luminescence transition level of ⁵D₀ → ⁷F₄. When Tb³⁺ ions are used as the sensitizer and at a specific concentration, the luminescence color transition of green → orange → red as the content of Eu³⁺ enhances. Analysis of the decay lifetime curves reveals that Tb³⁺ → Eu³⁺ energy transfers occur in the co-doped SGGO phosphors, with the mechanism identified as quadrupole–quadrupole interaction. This article investigates the specific energy transfer processes involved. The optimum content of Eu³⁺ is ascertained as 0.03. Under the excitation at 375 nm, the SGGO based phosphor containing 0.06 Tb³⁺ and 0.03 Eu³⁺ exhibits CIE coordinates of (0.5000, 0.4397).