基于Tb3+为桥梁的能量传递模型构建高效红色荧光粉的研究

The development of Eu3+/Sm3+-activated narrow-line red-emitting materials that can improve both color rendering and lumen equivalent in white light blends is one goal for phosphor development in light emitting diode (LED) systems. The low oscillator strength and narrow line width of Eu3+/Sm3+ f-f transitions makes it necessary to find sensitizers for Eu3+/Sm3+ luminescence that have allowed excitation bands that overlap with the typical emission wavelength of InGaN-based LEDs (350–420 nm). According to the transitions and energy transfer rulers of rare earth, the Tb3+ bridging model of energy transfer has been proposed in eulytite-type orthophosphate host for the design of efficient red-emitting phosphor. In order to achieve the goal of matching commercial UV LED chip, we explore ways and means to sensitize Eu3+/Sm3+ emission using activators that have dipole allowed transitions in the near-UV spectral regions. Moreover, with the aid of energy transfer, further studies on the relationships that describe the performance of the phosphor as a function of phosphor composition will be carried out, to provide the support of theoretical and experimental. The application span of Eu3+/Sm3+-activated narrow-line red-emitting phosphors will be further expanded, and promote the development of innovation of novel phosphors design concept.

以三价Eu3+、Sm3+等稀土离子激活的线状红光发射荧光粉在三基色白光模式中能够同时改善白光的显色性和白光LED器件的流明效率，而受到人们的广泛关注。本项目围绕三价Eu3+、Sm3+等离子的f-f跃迁在350 - 420 nm 的近紫外区域激发效率较低的问题而展开。申请人根据稀土离子跃迁和能量传递规则，提出在硅铋石型基质中利用Tb3+为桥梁的能量传递模型构建线状红光发射荧光粉的方案。分析桥连模型中敏化剂-桥连剂-激活剂稳定共存的方法及它们之间的相互作用机理，明确三价Eu3+/Sm3+离子的敏化机制，并结合硅铋石型基质的组成与结构调控，探索三价Eu3+/Sm3+离子激活的红色荧光粉在近紫外光谱区域能够被有效激发的途径和方法，为三价Eu3+/Sm3+离子的红光发射效率的提高提供理论指导与实验支持。该工作将拓宽三价Eu3+、Sm3+等线状红色荧光粉的应用范围，并推动新型荧光粉设计理念的创新发展。

以三价Eu3+、Sm3+等稀土离子激活的线状红光发射荧光粉在三基色白光模式中能够同时改善白光的显色性指数和白光LED器件的流明效率，而受到人们的广泛关注。本项目基于能量传递桥连模型的框架下，立足于通过能量传递来实现高效红光发射。通过基质的选择及组成与结构调控，采用高温固相法制备了Sr3Gd(1-m-n)Na(PO4)3F:mTb3+,nEu3+, Sr3La(1-m-n)Na(PO4)3F:mTb3+,n Eu3+/Sm3+等线状红光发射材料。分析桥连模型中不同掺杂离子稳定共存的方法及它们之间的相互作用机理，明确了三价Eu3+/Sm3+离子的敏化机制，并结合基质的组成与结构调控，澄清了三价Eu3+/Sm3+离子激活的红色荧光粉在近紫外光谱区域能够被有效激发的途径和方法，为三价Eu3+/Sm3+离子的红光发射效率的提高提供理论指导与实验支持。此外，利用X-射线多晶粉末衍射仪，通过Rietveld粉末结构精修的方法详细研究了硅铋石型化合物 Ba3Ln(PO4)3 (Ln = La, Y)的结构，揭示了结构调控与发光性质的一般规律。发现了在Sr3GdNa(PO4)3F:Tb3+,Eu3+系列荧光材料中存在的三重能量传递现象（Gd3+→Tb3+, Gd3+→Eu3+, and Tb3+→Eu3+）。上述研究工作将拓宽三价Eu3+、Sm3+等线状红色荧光粉的应用范围，并推动新型荧光粉设计理念的创新发展。在项目执行期间，在该项目基金的支持下共发表与课题相关SCI论文12篇，会议论文1篇，综述论文2篇。培养研究生3名。在国内学术会议作口头报告1次。本项目圆满完成了任务书中预定的研究目标，取得了预期的成果。