Abstract: Ba₃Bi_2-x(PO₄)₄∶xTb³⁺ (x=0.05, 0.1, 0.15, 0.3, 0.4, 0.5) green phosphors were prepared by high-temperature solid phase reaction. Samples were analyzed by X-ray diffraction apparatus, scanning electron microscopy, spectrophotometer, and fluorometric spectrometer. The results show that all samples are Ba₃Bi₂(PO₄)₄ pure phase. The band gap of Ba₃Bi_1.7(PO₄)₄∶0.3Tb³⁺ is estimated to be 4.21 eV. At the excitation of 377 nm, the peak of emission spectra of samples are 543 nm, 584 nm, and 619 nm, corresponding to the energy level transitions of ⁵D₄→⁷F₅, ⁵D₄→⁷F₄ and ⁵D₄→⁷F₃ of the Tb³⁺ ions, respectively. As the doping concentration of Tb³⁺ ions increases, the luminous intensity of the sample increases first and then decreases. When x is 0.3, the luminous intensity reaches the maximum. The calculations indicate that the nearest neighbor ion plays a major role in the concentration quenching of Ba₃Bi_2-x(PO₄)₄∶xTb³⁺ phosphors. The luminous intensity changes little with the test temperature increases, indicating excellent thermal stability of the sample. The CIE chromaticity coordinate indicates that the prepared samples can emit green light when excited by UV light.

Key words: Ba₃Bi_2-x(PO₄)₄∶xTb³⁺, eulytite type phosphate, high-temperature solid phase reaction method, green phosphor, rare earth doping, photoluminescence, energy level transition, thermal stability