KZnF3:Ce3+,Tb3+纳米粒子合成与发光

采用微乳液法合成了Ce3 ,Tb3 单掺和双掺KZnF3纳米晶。分析了样品的结构与形态,结果表明,所合成的样品均为单相,颗粒粒度分布均匀。讨论了光谱特性,并与高温固相法合成的产物作了对比。研究发现,KZnF3:Ce3 纳米晶的发射光谱与体相多晶相比,最强峰位置红移约35nm;在KZnF3纳米晶双掺体系中存在Ce3 →Tb3 能量传递,尤其是Tb3 的5D4→7F5跃迁发射显著增强,有望成为一种有发展前途的绿色荧光材料。

Synthesis and Fluorescence of KZnF3:Ce3+,Tb3+ Nanoparticles

Phosphors of KZnF3:Ce3 ,KZnF3:Tb3 and KZnF3:Ce3 ,Tb3 nanoparticles were synthesized in a cetyltrimethylammonium bromide(CTAB)/2-octanol/water microemulsion system.X-ray diffraction(XRD) pattern was used to identify the formation of KZnF3 phase without detectable impurity.Environment scanning electron microscopy(ESEM) image showed that the average sizes of the KZnF3:Ce3 ,Tb3 nanocrystals were 30 nm in diameter.Photoluminescence characteristics of the rare earth ions doped nanoparticles were investigated and compared with that of the sample prepared by solid state reaction at a high temperature.The emission peak of the KZnF3:Ce3 nanoparticles showed an obvious red shift as compared to that of polycrystalline powder.In a co-doped system of KZnF3 nanoparticles,the emission band of Ce3 even could hardly be observed and the luminescence intensity of Tb3 was increased much compared with that Tb-doped singly.This showed that the emission of the Tb3 was sensitized by Ce3 .The experimental results indicated that there was an effective energy transfer from Ce3 to Tb3 in KZnF3 nanoparticles.