用于白光LED的新型Eu2+/Tb3+/Sm3+或Eu2+/Sm3+共掺的红色荧光粉的制备、发光性质和晶体结构关系研究

As the fourth generation of lighting materials, white LED shows a broad application prospect in many lighting field, espectially in domestic lighting because of its low energy consumption, long service life, small volume, fast reponse, no pollution and other advantages. At present, the white LED phosphors, having most mature light conversion and most broad application, show low color rendering index because of lacking of a red component. This project is based on Eu2+→Sm3+ or Eu2+→Tb3+→Sm3+ two kinds of energy transfer models,in which Eu2+ ions are used as sensitizer and Tb3+ are used as energy transfer bridge. We will synthesize new white LED red phosphors doping Eu2+/Sm3+ or Eu2+/Tb3+/Sm3+ under nonreducing conditions.The effects of calcining temperature, doping concentration on the photoluminescent properties will be discussed, and the energy transfer mechanism will be summarized.Based on dielectric theory of chemical bond complex crystal, we will calculate properties of chemical bonds and environmental factors of matrixes, which makes teduction of Eu3+ under nonreducting conditions, makes Eu2+ ions have strong absorption in near ultraviolet and blue domain. We will deduce the law from the chemical bonds,environmental factors of matrixes, and the structure of crystals.Applying the law we can select the proper matrix. This opens up a new road for the development of new white LED luminescent materials.

作为第四代照明材料，白光LED因具有能耗低、寿命长、体积小、响应快、无污染等有优点而在众多照明领域尤其是在家用照明展现了广阔的应用前景。目前，应用最多也最成熟的光转换白光LED荧光粉因缺少红色成分而显色指数偏低。本项目依据Eu2+→Sm3+或Eu2+→Tb3+→Sm3+两种能量传递模型，以Eu2+作为敏化剂，Tb3+作为Eu2+和Sm3+之间能量传递的桥梁，拟设计在非还原条件下合成新型白光LED用Eu2+/Sm3+或Eu2+/Sm3+/Tb3+共掺杂的无机红色发光材料，研究煅烧温度、掺杂离子的浓度对发光性质的影响，阐明能量传递机理。利用复杂晶体的化学键介电理论分析计算能使Eu3+在非还原条件被还原，能使Eu2+在近紫外和蓝光区有强烈吸收，并能产生强红光发射的基质的化学键，环境因子特点以及结构性质规律，运用该规律指导选择基质。这为发展新型白光LED发光材料开辟了一条崭新的道路。

作为第四代照明材料，白光LED因具有能耗低、寿命长、体积小、响应快、无污染等优点而在众多照明领域尤其是在家用照明展现了广阔的应用前景。目前，应用最多也最成熟的光转换白光LED荧光粉因缺少红色成分而显色指数偏低。本项目合成了Tb3+ 和Sm3+掺杂BaFCl:Eu2+,SrB4O7:Eu2+,Sr4Al14O25:Eu2+,BaMgSiO4:Eu2+,CaAl2Si2O8:Eu2+,Lu(PO3)3:Eu2+，研究结果发现，共掺杂时在这些基质中没有出现能量传递。我们进一步研究了Sm2+ 在基质中的发光性质以及新的红色发光物质的开发和研究，并研究了Sm3+在空气气氛中煅烧时的还原现象.理论上我们推导出影响Eu3+和Sm2+发光强度的畸变因子和它的计算公式。意外地我们发现Tm3+/Sm3+，Dy3+/Eu3+, Tm 3+/Dy3+, Dy3+/Sm3+共掺杂可以通过调节稀土离子的浓度实现白光发射。这为发展新型白光LED开辟了一条新的道路。