Synthesis and Property Investigation on the Spherical Lu<sub>3</sub>Al<sub>5</sub>O<sub>12</sub>:Tb<sup>3+</sup> Phosphor with Green Emitting

Abstract

Spherical phosphors of (Lu1-xTbx)3Al5O12 [(Lu1-xTbx)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 (Lu1-xTbx)AG phosphors were tested by XRD, FE-SEM, PLE/PL, and fluorescence decay analysis. The phase pure (Lu1-xTbx)AG garnets were formed at 1100 °C or higher temperatures. The phosphors exhibited strong green emissions at ~545 nm (the 5D4→7F5 transitions of Tb3+) 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 Tb3+ content increasing to 7 at%, and then gradually decreases owing to the concentration quenching. The lifetime of 545 nm emission decreases at a higher Tb3+ addition. The spherical (Lu1-xTbx)AG garnet phosphors developed in the this work were expected to be widely used in lighting and displaying areas.