摘要
采用共沉淀结合高温分解方法合成了CaO:Eu3+红色长余辉发光材料.X射线衍射分析表明,随着温度的升高,产物相结构逐渐由碳酸钙的混合相变为单相结构,继而生成单相氧化钙结构.CaO:Eu3+的激发谱显示为255nm左右的一个宽激发带和393nm的激发峰,宽激发带来源于CaO晶格的电荷迁移(CTB),发射光谱对应于Eu3+的5D→7FJ(J=0,2,3,4)的跃迁.室温观察到CaO:Eu3+强的红色长余辉发射,热释光测量证实在CaO:Eu3+中存在深度大约为0.69eV的陷阱能级,这是CaO:Eu3+在室温具有红色长余辉的微观原因.存在的陷阱能级可能来源于Eu3+取代Ca2+进入晶格后,由于电荷的不等价替换而引入了电子陷阱.余辉衰减曲线的研究表明,样品的余辉发光可能与陷阱及发光中心之间的量子隧穿有关.
The red long-persistent phosphor CaO： Eu3＋ is prepared by a co-precipitation method with further thermal decomposition. The X-ray diffraction analysis shows that the crystal structure of calcium carbonate sample transforms into a single-phase structure and then generates a single-phase calcium oxide structure with the increase of sintering temperature. The excitation spectrum of CaO： Eu3＋ shows a broad band around 255 nm, which is attributed to the charge transfer of Eu3＋-O2-, and a sharp peak at 393 nm. The emission spectrum of samples correspond to Eu3＋ transitions between SD and 7FJ （J = 0, 2, 3, 4） electron configurations. The red long afterglow is observed at room temperature. A trap level located at 0.69 eV is found by thermolumihnescence measurement, which arises from the fact that Eu3＋ is substituted for Ca2＋ and enters into the lattice. The afterglow luminescence mechanism of sample was discussed according to quantum tunneling.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2012年第22期431-436,共6页
Acta Physica Sinica
基金
国家自然科学基金(批准号:20871033)资助的课题~~
