(Gd1-xTbx)3(Al1-yGay)5O12 green phosphors with high quantum yield and low thermal quenching via modulation the Ga3+ admixture

Highlights: • (Gd_1-xTb_x)₃(Al_1-yGa_y)₅O₁₂ phosphors synthesized through the solid-state reaction method. • The Ga³⁺ admixture tends to stabilize the garnet phase. • (Gd_0.9Tb_0.1)₃(Al_0.6Ga_0.4)₅O₁₂ phosphor exhibits high thermal stability and quantum efficiency. (Gd_1-xTb_x)₃(Al_1-yGa_y)₅O₁₂(x = 0.02–0.4, y = 0.2–1) garnet green phosphors were synthesized through the solid-state reaction method. The phase analyses and luminescence properties of phosphors were investigated as a function of the Ga³⁺ admixture content with the aim of development of thermal stable and efficient green phosphors. The results show that pure garnet was synthesized only when the Ga³⁺ content is high enough(y ≥ 0.4) and the optimal content of Tb³⁺ was 10 at.% Tb³⁺ (x = 0.1). The spectra intensity and the thermal stability of phosphors strongly depend on the Ga³⁺ content. The (Gd_0.9Tb_0.1)₃(Al_0.6Ga_0.4)₅O₁₂ phosphor has maximum emission intensity with a high quantum efficiency about 87.72%, and it has best thermal stability with a highest quenching temperature of 488 K. Therefore, the (Gd_0.9Tb_0.1)₃(Al_0.6Ga_0.4)₅O₁₂ phosphor is potential to be served as green phosphors in lightings and displays.