Eu^(3+)对Ba_3La(PO_4)_3:Dy^(3+)白光荧光粉发光性能的影响及发光机理的研究

Influence of Eu^(3+) Doping on Luminescent Properties of Ba_3La( PO_4)_3∶ Dy^(3+) White Phosphor and Its Luminescent Mechanism

采用高温固相法制备了Ba_3La_(1-x-y) (PO_4)_3:xDy^(3+),yEu^(3+)白光荧光粉,并通过XRD和荧光光谱性能分析手段对样品的物相组成、发光性能和发光机理进行了研究。结果表明:由于Eu^(3+)的掺杂影响了Ba_3 La(PO_4)_3:Dy^(3+)荧光粉的晶体场环境,在Dy^(3+)的~6F_(9/2)能级与Eu^(3+)的~5D_0能级间发生交叉弛豫,并通过能量共振转移,Dy^(3+)向Eu^(3+)传递能量,Ba_3 La_(1-x-y)(PO_4)_3:xDy^(3+),yEu^(3+)荧光粉在350 nm紫外光激发下同时出现了Dy^(3+)和Eu^(3+)的特征发射,发射光谱中增加了红光成分,改善了色温。实验得出Dy^(3+)和Eu^(3+)掺杂浓度分别为0.08和0.06时,荧光粉的发射光最接近于理想白光。

A series of Ba3La（ PO4）3∶ x Dy3 ＋,y Eu3 ＋phosphors were synthesized by solid state methods.The crystal structure,luminescent properties and mechanism of the phosphors were investigated by XRD and photoluminescence spectra. The results show that doped Eu3 ＋influence on the crystal field of Ba3La1-x-y（ PO4）3∶ x Dy3 ＋,y Eu3 ＋phosphors. The cross-relaxation phenomenon occur between the6F9 /2energy level of Dy3 ＋and5D0energy level of Eu3 ＋,and the energy transfer from Dy3 ＋to Eu3 ＋through the resonance energy transfer. The Ba3La1-x-y（ PO4）3∶ x Dy3 ＋,y Eu3 ＋phosphors under 350 nm ultraviolet excitation appear characteristic emission peaks of Dy3 ＋and Eu3 ＋. The emission spectra of the phosphors increase the red,improving the color tones. The experimental results show that the emitting light of the phosphors is the most close to the ideal white light,when Dy3 ＋and Eu3 ＋concentrations doped in the phosphors are 0. 08 and 0. 06,respectively.