Luminescence properties of double perovskite Gd₂MgTiO₆:Tb³⁺ phosphors by solid-state reaction method

A series of double perovskite (Gd_1−xTb_x)₂MgTiO₆ (x = 0.01, 0.05, 0.1, 0.15, 0.2, 0.3 and 0.4) phosphors were successfully synthesized by solid-state reaction method. The A-site in the host is occupied by two Gd³⁺ ions, which facilitates the doping of Tb³⁺ ions. The crystal structure, morphology and luminescence performance were evaluated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, photoluminescence and calculation of CIE color coordinates. A weak emission peak (⁵D₄–⁷F₆, 490 nm) and a strong emission peak (⁵D₄–⁷F₅, 545 nm) existed in the emission spectra under 313 nm excitation. The quenching concentration of Tb³⁺ reached up to 20.0 mol% was observed in Gd_1.8Tb_0.2MgTiO₆ phosphors. In order to explore the potential application of Gd_2−2xMgTiO₆:xTb³⁺ phosphors in white LED solid-state lighting, the fluorescence decay curves and thermal stability were carried out.