The Effects of Rare-Earth Co-Dopants on Green Long-Lasting Phosphorescence and Thermoluminescence Properties of Ca8Mg ( SiO4 ) 4Cl2 : Eu2 + , RE3 +
The Effects of Rare-Earth Co-Dopants on Green Long-Lasting Phosphorescence and Thermoluminescence Properties of Ca8Mg ( SiO4 ) 4Cl2 : Eu2 + , RE3 +
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DOI：
10.1149/1.3327891
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发表时间：
2010-05
影响因子：
3.9
通讯作者：
Baohong Li;Jinsheng Shi;Wanhui Zhang;Jing Wang;Q. Tang;Q. Su
中科院分区：
文献类型：
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作者：
Baohong Li;Jinsheng Shi;Wanhui Zhang;Jing Wang;Q. Tang;Q. Su
系统地研究了系列绿色长余辉发光材料Ca8 Mg(SiO4)4Cl2：Eu2+，RE3+(RE=La-Lu)的长余辉发光和热释光光谱。由于Eu2+离子的4f6 d→4f7跃迁，在5 0 2 nm处绿色磷光占主导地位。它强烈依赖于共掺的稀土离子，其性能的大小顺序为：ND>；Sm>；Ho>；Dy&Gt；Ce&Gt；Pr&Gt；La&Gt；Gd&Gt；TM&Gt；Er&Gt；Tb&Gt；Lu；对于Yb离子，磷光完全熄灭。热释光性质表明，在293-577K的温度范围内，一般在330、370、435和470K附近有四个峰，与稀土离子等价取代引起的外来缺陷有关。长余辉发光与热释光性质的关系表明，在300-400K温度范围内，与热释光特性有关的陷阱深度、电荷俘获中心和俘获电荷密度的差异是导致绿色长余辉发光有规律变化的原因。用一般动力学模型对Ca8-Mg(SiO4)4Cl2：Eu2+，Nd3+的热释光谱进行了拟合。在本实验中，最合适的陷阱深度为0.8 eV左右，动力学序参数b为1.14。
A series of green long-lasting phosphorescence materials Ca 8 Mg(SiO 4 ) 4 Cl 2 :Eu 2+ ,RE 3+ (RE = La-Lu) was systematically investigated by long-lasting phosphorescence and thermoluminescence spectra. The green phosphorescence predominates at 502 nm due to the 4f 6 d → 4f 7 transition of the Eu 2+ ion. It strongly depends on the co-doped rare-earth ion, and its performance decreases in the order Nd > Sm > Ho > Dy > Ce > Pr > La > Gd > Tm > Er > Tb > Lu; for the Yb ion, the phosphorescence is totally quenched. The thermoluminescence properties show that there are generally four peaks around 330, 370, 435, and 470 K in the temperature range of 293-577 K, associated with the foreign defects due to the aliovalent substitution of rare-earth ions. The relationship of the long-lasting phosphorescence and thermoluminescence properties show that the difference in trap depth and the density of charge trapping centers and trapped charges, associated with thermoluminescence characteristics in the temperature range of 300-400 K, is responsible for the regular variation in the green long-lasting phosphorescence. The thermoluminescence spectrum of Ca 8 Mg(SiO 4 ) 4 Cl 2 :Eu 2+ ,Nd 3+ is fitted by the general kinetic model. The most appropriate trap depth in the present host is estimated to be around 0.8 eV, and the kinetic-order parameter b is 1.14.