Pr^(3+)掺杂SrWO_4荧光材料的制备与发光性能的研究

Preparation of Pr^(3+) doped SrWO_4 fluorescent material and its luminous performance

通过化学共沉淀法合成了不同Pr3+掺杂浓度的Sr WO4荧光材料,运用X射线衍射仪、扫描电镜测试手段对样品进行了结构与形貌表征。测量了各样品的发射和激发光谱,研究了激活剂Pr3+的摩尔分数对发光强度的影响,确定了Pr3+掺杂钨酸锶荧光材料最佳摩尔分数为7%,Sr WO4:Pr3+荧光材料的发射光谱由1个宽带峰和一些窄带峰组成,可以被紫外光有效地激发,300~500 nm处的宽带峰是WO2-4的自激发发射,即W6+→O2-电荷迁移态的发射,峰值位于425 nm处。500~700 nm处的窄带发射峰分别归属于Pr3+的1D2→3H4、3P0→3H6和3P0→3F2跃迁,在644 nm(3P0→3F2)处得到最强的红光发射。随着掺杂摩尔分数的增加,发光强度降低,发生了浓度猝灭。

SrWO4 fluorescent materials doped with different concentrations of Pr3 ＋ are prepared by chemical coprecipitation method. The X-ray diffraction and scanning electron microscopy （SEM） are used to characterize the structure and morphology. The excitation and emission spectra of each sample are measured. The effect of different doping concentrations of Pr3 ＋ activator on luminescence intensity is studied. The optimal molar fraction of the Pr3 ＋ doped tungsten acid strontium is 7%. The emission spectrum of SrWO4 ： Pr3＋ fluorescent material, which can be effectively excited by ultraviolet, has a broad peak and some narrow peaks. The broad peak at 300 -500 nm （Amax = 425 nm） is attributed to the self-excitation of WO4 2- ,namely the emission of W6＋→O2- charge transfer state. The narrow peaks at 500 -700 nm are attributed to 1D2→3H4 ,3P0→3H6 and 3p0→3 F2 of Pr3＋ transition. The strongest red emission can also be reached at 644 nm due to 3P0 →3F2. However, increasing the doping concentration leads to the decrease of the emission intensity, due to the concentration quenching.