Eu^3＋掺杂CaWO4红色荧光粉发光性质的浓度依赖关系研究

Study of concentration dependence of luminescent properties for Eu^(3+) doped CaWO_4 red phosphors

采用共沉淀法制备了不同Eu^(3+)掺杂浓度的CaWO_4荧光粉材料.通过X射线衍射和场发射扫描电镜技术对样品的结构和形貌进行了表征.测量了各样品的激发光谱、发射光谱和荧光衰减曲线,计算了各样品的部分Judd-Oflet(J-O)参数和~5D_0(Eu^(3+))能级量子效率,以及荧光粉的色坐标,讨论了样品电荷迁移带相对强度、J-O参数、量子效率与掺杂浓度的依赖关系.对Eu^(3+)掺杂的CaWO_4发光材料的光致发光性质的研究表明,在CaWO_4:Eu^(3+)中~5D_0→~7F_2跃迁的616 nm红色发光能被394.5 nm和465 nm的激发光有效激发,具有近紫外(或蓝光)激发效率高和猝灭浓度大的优点,有潜力成为高效的近紫外(或蓝光)激发白光发光二极管用红色荧光粉材料.

Eu^3＋ doped CaWO4 phosphors of different concentrations are prepared by a co-precipitation method. The X-ray diffraction patterns and field emission scanning electron microscopy images are investigated. The excitation spectra, emission spectra and the curves of fluorescence decays of the samples are measured. The Judd-Ofelt （J-O） parameters, quantum efficiencies of the 5^Do level of Eu^3＋ and color coordinates are calculated. The dependences of relative intensity of charge transfer band, J-O parameter and quantum efficiency on doping concentration are discussed. The photoluminescence properties of Eu^3＋ doped CaWO4 luminescent material are studied. The results indicate that the 616 nm red emission of Eu3＋→5Do→7^F2 transition can be effectively excited by 394.5 nm and 465 nm with high excitation efficiency and the concentration quenching is high. So the CaWO4： Eu red phosphor may have a potential application for white light emitting diode.