均相有序双钙钛矿Sr_2CaMoO_6:Eu^(3+)荧光粉的制备及其发光性能  

Preparation of homogeneous and ordered double-perovskite Sr_2CaMoO_6:Eu^(3+) phosphors and its luminescent properties

作　　者：张乐[1] 李月[1] 刘金秋[1] 韩朋德[1] 张其土[1] 

机构地区：[1]南京工业大学材料科学与工程学院,江苏南京210009

出　　处：《南京工业大学学报（自然科学版）》2012年第5期30-37,共8页Journal of Nanjing Tech University(Natural Science Edition)

基　　金：江苏省普通高校研究生科研创新计划项目(CXZZ12_0410);江苏高校优势学科建设工程资助项目

摘　　要：采用乙二胺四乙酸(EDTA)-柠檬酸联合配位法在较低温度下制备Eu3+掺杂的双钙钛矿Sr2CaMoO6橙红色荧光粉,借助X线衍射、扫描电镜、紫外可见漫反射光谱和荧光光谱研究不同煅烧温度下粉体的结构和发光性能,并进行结构精修和态密度的第一性原理计算。结果表明:在900℃下即得到B位高度有序的离子掺杂的双钙钛矿粉体,其结构为BO6八面体周期性间隔排列且小角度倾斜的空间群为P21/n的正交双钙钛矿结构;粉体在近紫外区强而宽的吸收源于MoO6八面体中O 2p轨道到Mo 4d轨道的电荷迁移,并由此发射以无禁戒的磁偶极跃迁橙光为主,但在蓝光激发下以发射宇称禁戒部分解除的电偶极红光为主;随着煅烧温度的升高,粉体的晶粒尺寸、B位有序度及颗粒尺寸都增大,1 100℃下煅烧的粉体具有最高的发光强度。Eu3＋ doped double perovskite Sr2CaMoO6 orange-red phosphor was prepared by EDTA-citric acid complexing method at a lower temperature.The X-ray diffraction,scanning electron microscope,UV-Vis diffuse reflection spectrum,and photoluminescent spectra were used to characterize the structure and luminescent properties of phosphors at different calcination temperatures,and the structure refinement of the prepared powder and its first principle calculations for density of states were displayed.Results showed that the highly B site-ordered ions-doped double perovskite powder obtained only at 900 ℃ and its structure with P21/n space group had a interval arrangement of BO6 octahedron with a slight tilting.The strong and wide absorption in UV region was resulted in the charge transfer from O 2p orbit to Mo 4d orbit and the resulted emission was dominated by magnetic dipole transition of orange light without prohibiting.The emission excited by blue light was dominated by the electronic dipole transition of red light with partial remove of parity.With increasing the calcination temperature,the grain size,the degree of B site-order and the particlal size were all grown up and the phosphor calcined at 1 100 ℃ had the highest luminescent intensity.

关 键 词：双钙钛矿 EDTA-柠檬酸联合络合法 荧光粉 白光LEDs 

分 类 号：O482.31[理学—固体物理]