Ba3Bi2(PO4)4∶Tb3+荧光粉的制备与性能研究

利用高温固相反应法制备出Ba₃Bi_2-x(PO₄)₄∶xTb³⁺(x=0.05,0.1,0.15,0.3,0.4,0.5)绿色荧光粉。通过X射线衍射仪、扫描电子显微镜、积分球式分光光度计和荧光光谱仪等对样品进行了分析。结果表明,所制备的样品均为Ba₃Bi₂(PO₄)₄纯相,Ba₃Bi_1.7(PO₄)₄∶0.3Tb³⁺的带隙估计值为4.21 eV。当激发光的波长为377 nm时,样品的发射光谱的波峰位于543 nm、584 nm和619 nm处,分别对应于Tb³⁺的⁵D₄→⁷F₅、⁵D₄→⁷F₄和⁵D₄→⁷F₃的能级跃迁。随着Tb³⁺掺杂浓度的增加,样品的发光强度先增强后减弱,当x=0.3时,发光强度最大。计算表明最近邻离子在Ba₃Bi_2-x(PO₄)₄∶xTb³⁺荧光粉的浓度猝灭中起主要作用。随着测试温度的升高,发光强度变化不大,表明样品具有优异的热稳定性能。CIE色坐标图表明所制备的样品可以被紫外光有效激发而发出绿光。

Preparation and Property of Ba3Bi2(PO4)4∶Tb3+ Phosphors

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.