Synthesis and photoluminescence of Gd₂O₂S: Tb³⁺ nanoaggregates via one-pot solvothermal method

Terbium ions doped gadolinium oxysulfide nanoaggregates have been successfully synthesized by one-pot solvothermal method. The undoped Gd₂O₂S show near-spherical structure with the diameter of ~400 nm. The XRD pattern shows pure hexagonal Gd₂O₂S phase can be obtained at 220 °C for 24 h. When the Gd₂O₂S doped with 7% Tb³⁺ ions, compared with the undoped samples, the phases at different temperature changed slightly, but the morphologies are greatly affected. Under ultraviolet (UV) light excitation, Gd₂O₂S:Tb³⁺ nanoaggregates exhibit green emissions at 490 nm, 545 nm, 588 nm and 621 nm, corresponding to the ⁵D₄→⁷F_J (J=3, 4, 5 and 6) transitions of Tb³⁺ ions, respectively. The quenching concentration of Tb³⁺ ions is 3% with the longest fluorescent lifetime of t₁=162 μs and t₂=57514 μs.