Eu3+激活的La2Mo2O9红色荧光粉的制备与性能

利用高温固相法制备了Eu³⁺掺杂的La₂Mo₂O₉红色荧光粉,并对这种荧光粉的结构及发光性质进行了研究。XRD结果表明,实验合成了单一立方相的La₂Mo₂O₉荧光粉体。该荧光粉的激发光谱由一宽带和一系列的锐峰组成;发射光谱由一系列锐峰组成,这些都与Eu³⁺的特征跃迁⁵D_J(J=0,1)和⁷F_J(J=1~4)相对应。结果表明该荧光粉可被395nm的紫外光和470nm的可见光有效激发,并发出峰值位于620nm左右的红光,亮度可达到传统红色荧光粉Y₂O₂S:Eu³⁺的1.5倍以上,这表明它可以作为蓝+黄模式白光LED的红色补光粉,也可以作为UV-LED激发三基色荧光粉体系中的红色荧光粉。研究了Eu³⁺的掺杂浓度以及不同助熔剂对样品发光性质的影响。Eu³⁺的摩尔分数为0.3时,发光强度达到最强。质量分数为3%的NH₄Cl作为助熔剂时效果最好。

Fabrication and properties of Eu3+ doped La2Mo2O9 red phosphor

A new red phosphor Eu³⁺ doped La₂Mo₂O₉ have been prepared by high temperature solid state method at 850℃ and the structure and luminescent properties of this phosphor were investigated. The XRD patterns show that single cubic phase La₂Mo₂O₉ crystal is synthesized in this experiment. The luminescent properties were studied by the excitation and emission spectra. The excitation spectra are composed of a broad band and a series of narrow bands; the excitation spectra include many narrow bands, which attribute to the intrinsic transition from ⁷F_J (J=1~4) to ⁵D_J (J=0, 1) of Eu³⁺. The results indicate that this phosphor can be excited by UV light of 395 nm and visible light of 470 nm, also emit red light at about 620 nm. The luminescent intensity of this phosphor is more than 1.5 times of that of Y₂O₂S:Eu³⁺, thus it can be used as red phosphor in the system of UV-LED based and blue-LED based white LED. The effects of Eu³⁺ molar concentration and flux on the luminescence properties were studied in this paper. The results show the intensity will reach the strongest when the molar concentration of Eu³⁺ is 30%; the NH₄Cl is the appropriate flux and its most suitable mass fraction is 3%.