溶胶-凝胶法合成Sr3MgSi2O8:Eu3+ 红色荧光粉及其发光性能

采用溶胶-凝胶法合成了Sr_3MgSi_2O_8∶Eu~(3+)红色荧光粉,并通过X射线衍射(XRD)、傅立叶变换红外光谱(FTIR)、扫描电镜(SEM)以及荧光光谱(PL)、X射线光电子能谱(XPS)等分析方法,对不同烧结温度(950,1 050,1 150,1 250℃)热处理4 h后得到的粉体的物相、形貌及发光性能进行了表征分析。由XRD表征结果可知,制备出的样品为正交晶系的Sr_3MgSi_2O_8;由扫描电镜及比表面积的测试结果可知,经过1 150℃热处理得到的荧光粉具有最大比表面积,可达到90.213 1 m~2/g,且粒径大小均一;由红外光谱图可知:样品中含有Si—O—Si、Mg—O和Sr—O化学键;在394 nm的激发波长下,所有样品在614 nm和702 nm处出现了强发射峰,分别对应于Eu~(3+)的~5D_0→~7F_2和~5D_0→~7F_4跃迁,属红光发射。随着热处理温度的升高,样品所对应的发射峰强度呈现出先增大后减小的变化趋势,即出现温度猝灭效应;经1 150℃热处理合成的Sr_3MgSi_2O_8∶Eu~(3+)红色荧光粉的发光性能最好,即最佳的热处理温度为1 150℃。

Synthesis of Sr3MgSi2O8:Eu3+ Red Phosphor by Sol-gel Method and Its Luminescence Properties

In this paper, Sr₃MgSi₂O₈:Eu³⁺ red phosphor was synthesized by sol-gel method. The phase, morphology and luminescence properties of the powders obtained by calcination at different temperatures (950, 1 050, 1 150, 1 250℃) were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), fluorescence spectrum (PL) and X-ray photoelectron (XPS). According to the results of XRD, the prepared sample is orthorhombic Sr₃MgSi₂O₈. The results of scanning electron microscopy and specific surface area show that the phosphor obtained by heat treatment at 1 150℃ has the largest specific surface area, which can reach 90.213 1 m²/g. In addition, the diameter is uniform; the infrared spectrum shows that the sample contains Si-O-Si, Mg-O and Sr-O chemical bonds; all samples show strong emission peaks at 614 nm and 702 nm, corresponding to the⁵D₀→⁷F₂ and ⁵D₀→⁷F₄ transitions of Eu³⁺ when the excitation wavelength is 394 nm, which belongs to red light emission. As the heat treatment temperature increases, the intensity of the emission peak corresponding to the sample first increases and then decreases, that is, the temperature quenching effect occurs. The Sr₃MgSi₂O₈:Eu³⁺ red phosphor synthesized by heat treatment at 1 150℃ has the best luminescence performance. The optimum heat treatment temperature is 1 150℃.