Preparation of (Y_1-x-y, La_y)₂O₃:xEu³⁺ red phosphors by microwave-assisted homogeneous precipitation method

A series of (Y_1-x-y, La_y)₂O₃:xEu³⁺(x=0.01~0.05, y=0.05~0.25) red phosphors were synthesized by microwave-assisted homogeneous precipitation method. The effects of doping density of Eu³⁺ and La³⁺, the calcining temperature on the characteristics of lumen-escence were investigated. The TG and FTIR curves of precursor, crystal structure, surfacemorphology, particle size and spectral characteristics of the samples were also investigated by differential thermal analysis, infrared spectroscopy, X-ray diffraction, SEM and fluoresc-ence spectrophotometer. The results indicate that the composition of precursor is (Y, La, Eu) OHCO₃·nH₂O and the as-prepared samples are cubic system. The SEM show that the samples are uniformly dispersed spherical phosphors particles with particle size of being about 200 nm. The optimum calcining temperature is 900 ℃. The optimum emission intensity of 614 nm is obtained when the x=0.03, y=0.1, 614 nm is corresponding to ⁵D₀→⁷F₂ transitionof Eu³⁺ ions in emission spectrum. The color coordinates of the sample is (0.654, 0.346).(Y_1-x-y, La_y)₂O₃:xEu³⁺ phosphors have good color purity and luminous intensity.