基于共聚阴离子设计发光颜色可调的硼磷酸盐荧光粉

Designing Color-tunable Emission Borophosphate Phosphors Via Co-polyanion Strategy

通过替代阴离子基团设计和合成系列发光颜色可调的硼磷酸盐Ba2Ca(PO4)2-x(BO3)x:Eu^2+(0≤x≤0.25)荧光粉。利用X射线衍射(XRD)、瞬态和稳态光谱、荧光量子效率多种手段对系列荧光粉的物相结构和发光特性进行了详细研究。XRD结果证实了BO3基团部分替换基质Ba2Ca(PO4)2中PO4单元没有显著改变基质的晶体结构框架。三角平面结构(BO3)替代四面体结构(PO4)使得基质晶胞发生了畸变,增加Eu^2+离子5d能级劈裂,使得荧光粉的发射峰在紫外光波长365 nm激发下出现连续红移,发射主峰从464 nm(x=0)红移至490 nm(x=0.25),实现了发光颜色从青光至黄绿光的连续调控。此外,通过荧光寿命和激发光谱研究了BO3替代PO4对样品中Eu^2+中心的局部结构的影响。

A series of color-tunable emissive Ba2Ca(PO4)2-x(BO3)x:Eu^2+(0≤x≤0.25)phosphors were designed and synthesized via substituting anionic building blocks.The phased structure and luminescent properties of the phosphors were investigated by X-ray diffraction(XRD),photoluminescence,lifetime and quantum efficiency.XRD patterns revealed that the samples Ba2Ca(PO4)2-x(BO3)x:Eu^2+ maintained single phase after doping the BO3 groups.The anionic polyhedron substitution of BO3 for PO4 induces a distinct microstructure acting on Eu^2+ ions.A continuous redshift,PL band center moves from 464 nm(x=0)to 490 nm(x=0.25),is observed in the PL spectra trend as x increases under the same excitation light(365 nm),achieving continuous regulation of the luminescent color from cyan to yellow-green.In addition,the microenvironment of the luminescent center(Eu^2+)in the phosphors was investigated by PLE spectra and fluorescence lifetime.