Synthesis and Property Investigation on the Spherical Lu_3Al_5O_(12):Tb~(3+) Phosphor with Green Emitting

摘要

Spherical phosphors of (Lu_(1-x)Tb_x)_3Al_5O_(12) [(Lu_(1-x)Tb_x)AG] have been obtained through homogeneous precipitation method using urea as the precipitant and rare earth nitrate as mother salts. The synthesis, phase evolution and photoluminescent properties of the (Lu_(1-x)Tb_x)AG phosphors were tested by XRD, FE-SEM, PLE/PL, and fluorescence decay analysis. The phase-pure (Lu_(1-x)Tb_x)AG garnets were formed at 1100 °C or higher temperatures. The phosphors exhibited strong green emissions at ～545 nm (the ~5D_4→~7F_5 transitions of Tb~(3+)) under ～276 nm excitation. The CIE chromaticity coordinates and color temperature were determined to be (～0.36, ～0.56) and ～5100 K, respectively. The intensity of 545 nm emission increased with the Tb~(3+) content increasing to 7 at%, and then gradually decreases owing to the concentration quenching. The lifetime of 545 nm emission decreases at a higher Tb~(3+) addition. The spherical (Lu_(1-x)Tb_x)AG garnet phosphors developed in the this work were expected to be widely used in lighting and displaying areas.