SynthesisandluminescentpropertiesofBaGd2O4:Eu3+phosphorswithhighlyefficientred-emitting

The BaGd2-2 xEu2 xO4（BG, x = 0.01-0.09） phosphors were successfully synthesized via the sol-gel method,and BaY2-2 yEu2 yO4（BY, y = 0.005-0.07） phosphors were included for comparison. The pure phase BG phosphors with the ordered CaFe2 O4-type structure are obtained by annealing at 1300℃ for5 h. The phosphors with uniform particle size of 120 nm and good dispersion display typical Eu3+emission with the strongest peak at 613 nm（5 D0→7 F2 transition of Eu3+） under optimal excitation band at 262 nm（CTB band）. The presence of Gd3+ excitation bands on the PLE spectra monitoring the Eu3+emission directly proves an evidence of Gd3+-Eu3+ energy transfer. Owing to the concentration quenching, the optimum content of Eu3+ addition is 5 at%（x = 0.05）, and the quenching mechanism is determined to be the exchange reaction between Eu3+. All the BG samples have similar color coordinates and temperature of（0.64 ± 0.02, 0.36 ± 0.01） and 2000 ± 100 K,respectively. The lifetime value of BaGd1.9Eu0.1O4 for 613 nm is fitted to be 2.19 ± 0.01 ms, and the Eu3+ concentration does not change the lifetime significantly. Owing to the Gd3+-Eu3+ energy transfer, the luminescent intensity of the BaGd1.9Eu0.1O4 phosphor is better than BY system. The BG system served as a new type of phosphor is expected to be widely used in lighting and display areas.