Enhanced Dy(3+) white emission via energy transfer in spherical (Lu,Gd)(3)Al(5)O(12) garnet phosphors

The Dy(3+) doped (Lu,Gd)(3)Al(5)O(12) garnet phosphors with spherical morphology were obtained via homogeneous precipitation method, followed by calcination at 1100 °C. The particle morphology does not change significantly, but can be controlled by adjusting the urea content. The synthesis, structure, luminescent properties of precursor and resultant particles were analyzed by the combined technologies of XRD, FE-SEM, PLE/PL decay behavior. The (Lu(0.975)Dy(0.025))AG phosphors display strong blue and yellow emission at ~481 nm ((4)F(9/2) → (6)H(15/2) transition of Dy(3+)) and ~582 nm (4)F(9/2) → (6)H(13/2) transition of Dy(3+)), respectively. The phosphors have similar color coordinate and temperature of (~0.33, ~0.34), ~5517 K, respectively, which are closed to the white emission. The particle size and luminescent intensity decreased while the lifetime increased with the urea concentration increasing. The Gd(3+) addition does not alter the shape/position of emission peaks, but enhance the blue and yellow emission of Dy(3+) owing to the efficient Gd(3+) → Dy(3+) energy transfer. The [(Lu(1-x)Gd(x))(0.975)Dy(0.025)](3)Al(5)O(12) phosphors are expected to be widely used in the lighting and display areas.