YAG∶Ce,Tb粉体的共沉淀法制备与发光性能

YAG∶Ce,Tb Powders Prepared by Co-precipitation Method and Their Luminescent Properties

以NH4HCO3溶液为沉淀剂,采用共沉淀法制备了前驱体,在氩气气氛中经1200℃煅烧2h合成了Y2.94-xCe0.06TbxAl5O12(YAG∶Ce,Tb)粉体。利用X射线衍射仪、透射电子显微镜、荧光光谱仪对样品的结构、形貌及发光性能进行了表征。所得粉体为体心立方相YAG∶Ce,Tb。粉体颗粒团聚成珊瑚虫形。YAG∶Ce,Tb粉体的激发光谱有3个激发带,峰值分别位于275nm(Tb3+的4f8→4f75d1跃迁)、341nm和450～470nm(Ce3+的4f1→4f05d1跃迁)。用275nm的紫外线激发YAG∶Ce,Tb粉体,得到了Tb3+和Ce3+的特征发射带。用460nm的蓝光激发YAG∶Ce,Tb粉体,其发射光谱中只有1个宽发射带,峰值位于531nm处,归属于Ce3+的4f05d1→2F7/2、2F5/2跃迁,而没有出现Tb3+的特征发射峰。对YAG∶Ce,Tb粉体中,在Tb3+与Ce3+之间Tb3+→Ce3+的能量转移机理进行了讨论。

The precursors were prepared via a co-precipitation method using NH4 HCO3 solution as the precipi tator. Then, Y2.91-xCe0.06TbxAl5O12（YAG：Ce,Tb） powders were obtained by calcining the precursors at 1200 ℃ for 2 hours in argon atmosphere. The structure, morphology and luminescent properties of the powders were characterized by X-ray diffraction（XRD）, transmission electron microscope（TEM） and photoluminescence method. The YAG ： Ce,Tb powder had a body centered cubic structure. The YAG ： Ce,Tb particles were agglomerated and coral-like in shape. The excitation spectra of YAG ： Ce,Tb powders consist of three excitation bands at 275nm（4f^8→4f^75d^1 transition of Tb^3＋ ）, 341nm and 450-470nm（4f^1→4f^05d^1 transition of Ce^3＋ ）, respectively. When excited with a ultraviolet light of 275 nm, YAG ： Ce,Tb powders showed characteristic emission bands of Tb^3＋ and Ce^3＋. When excited with a blue light of 460nm, YAG ： Ce,Tb powders showed only a broad emission band peaking at 531nm, which was attributed to 4f^05d^1→^2F7/2、^2F5/2 transitions of Ce^3＋ . However, the characteristic emission bands of Tb^3＋ in YAG ： Ce, Tb powders were not detected. The energy transfer of Tb^3＋→Ce^3＋ in YAG ： Ce,Tb powders was also discussed.