M_2Eu_xLn_(1-x)AlO_5(M=Ca,Sr,Ba,Ln=La,Gd,Lu)红色荧光粉发光性质的研究

用高温固相反应法合成了M_2Eu_xLn_(1-x)AlO_5(M=Ca,Sr,Ba,Ln=La,Lu,Gd)荧光粉,研究了荧光粉的发光性质。在紫外光和近紫外光激发下,样品的发射光谱由Eu~(3+)的5D0→7FJ(J=0,1,2,3,4)特征发射组成。其中Eu3+离子位于590 nm附近的5D0→7F1和位于620 nm附近的5D0→7F2跃迁发射的强度最强。荧光粉的激发光谱都是由O~(2-)-Eu~(3+)电荷迁移带和Eu~(3+)的f-f跃迁构成的。M_2Eu_xLa_(1-x)AlO_5(M=Ca,Sr,Ba)的O2--Eu~(3+)的电荷迁移带的峰位按Ca、Sr、Ba顺序向长波方向移动。研究了用La、Gd和Lu替代M_2Eu_xLn_(1-x)AlO_5中Ln的位置对样品发光的影响。给出了Eu~(3+)浓度对发光强度的影响。分析了M_2Eu_xLn_(1-x)AlO_5和M_2Eu_xLn_(1-x)AlO_5的荧光寿命。

Photoluminescence Properties of M2EuxLn1-xAlO5(M =Ca,Sr, Ba,Ln =La,Gd, Lu) Red Phosphor

The red emitting phosphors M₂Eu_xLn_1-xAlO₅ (M=Ca, Sr, Ba, Ln=La, Lu, Gd) were synthesized through the solid state reaction technique. The photoluminescence properties were described. Upon excitation with UV and near UV light excitation, the photoluminescence emission spectra could be assigned to the transitions of Eu³⁺ from the initial state ⁵D₀ to the final states ⁷F_J (J=0,1,2,3,4). The two strong emissions peaked at 590 nm and 620 nm, which arose from the ⁵D₀-⁷F₁ and ⁵D₀-⁷F₂ transitions of Eu³⁺, respectively. The photoluminescence excitation spectra show abroad O^2--Eu³⁺ charge-transfer band and f-f transitions. O^2--Eu³⁺ charge-transfer bands of M₂Eu_xLa_1-xAlO₅ (M= Ca,Sr,Ba) shift to the longer wavelength in order of Ca, Sr, Ba. The replacement of Ln in Sr₂Eu_xLn_1-xAlO₅ by La, Gd and Lu was studied. The dependence of the integrated luminescence intensities on Eu³⁺ concentration was presented. The lifetimes of Sr₂Eu_xLa_1-x-AlO₅ and Sr₂Eu_xGd_1-xAlO₅ were analyzed.