表面改性剂对CaCO_3:Eu^(3+)荧光粉发光性能的影响

Effect of Surface Modifier on Luminescence of CaCO_3:Eu^(3+) Phosphor

采用微波共沉淀法制备了CaCO3:Eu3+红色荧光粉,然后分别用硬脂酸和钛酸酯偶联剂(TC-114)对其进行改性,研究改性前后荧光粉的结构和发光性能的变化。激光粒度和X射线衍射分析表明,经硬脂酸改性后的荧光粉粒径有所增加,而经钛酸酯偶联剂改性后的荧光粉粒径有所减小,改性前后结构未发生变化。红外光谱与热重分析表明,硬脂酸和钛酸酯偶联剂与荧光粉表面羟基发生了化学键合。荧光光谱测试表明,经硬脂酸改性的CaCO3:Eu3+红色荧光粉荧光强度增强,而经钛酸酯偶联剂改性后其荧光强度明显减弱,可能是由改性剂自身结构以及改性前后荧光粉表面的羟基数量和猝灭中心数量不同所致。

The CaCO3：Eu3＋ red phosphor synthesized by a microwave method was modified via stearic acid and titanate coupling agent （TC-114）, respectively. The structure and luminescence properties of unmodified and modified phosphor were investigated. The grain size analysis indicated that the size of CaCO3：Eu3＋ phosphor modified by stearic acid increased, but the size by titanate coupling agent decreased. The structures of unmodified and modified phosphor did not change. It was also revealed that stearic acid and titan- ate coupling agent were chemically bonded onto the surface of phosphor. The luminescence intensity of phosphor modified by stearic acid could be enhanced, however, the luminescence intensity of phosphor modified by titanate coupling agent could be weakened. This might be due to the structure of modifier and the number of the hydroxyl as well as the quenching of unmodified and modified phosphor.