利用多面体模块构建新型荧光材料基质及其对发光性能的调控研究

There will be important scientific significances on the development of the novel phosphor hosts and the investigation of relationship between structure and property from the viewpoint of mineral crystal chemistry. The garnet-, apatite- and melilite-type compounds used as phosphor hosts will be regared as the main research objects and models, and some proper polyhedron modules, anions and cations will be selected and modified to construct the novel phosphor hosts based on their high symmetry and complex chemical components. The restriction of different types of iso-structural compounds will be eliminated. Therefore, some new inorganic solid solutions with garnet-, apatite- and melilite-type mineral structure, and some new phases with derived structure from the initial mineral will be formed based on the designed single (multiple) modules. By using the strategies of crystal growth, single crystal structure solving technique and powder structure Rietveld refinement, some new crystal structures will be resoveld. The effect of stability of structural phase and some rules on the phase formation will be discussed from the comprehensive consideration of type, charge, size, and distortion of the polyhedrons, anions and cations. Some new preparation method will be also devoloped to prepare new phosphors with pure phase. Accordingly, the relationship and inner mechanism on the host composition, structure and luminescence property of the Eu2+ and Ce3+-doped luminescence materials will be demonstrated, and the fine control of the excitation and emission wavelength, as well as the enhancement of luminescence intensity and efficiency and chemical/thermal stability will be accomplished in this project. So the experimental evidences in the field of the white light emitting diodes (LEDs) phosphors, plasma display plane (PDP) phosphors and the long lasting phosphorescence (LLP) phosphors will be establised for the fundamental and application researches.

从矿物晶体化学入手开发新型荧光材料基质，探讨结构与发光性能关联规律具有重要科学意义。本项目以无机荧光材料中常见的石榴石、磷灰石和黄长石结构为模型，根据其对称性较高而化学组分相对复杂的特点，利用无机多面体模块和相应的阳、阴离子组合替换并构建新型荧光材料基质，结构设计中突破异质同构化合物类型的限制，获得由新型单一(复合)模块构筑的同构固溶体或衍生结构新相。通过晶体生长、单晶结构解析和粉晶Rietveld结构精修等技术确定新物相晶体结构，分析结构中多面体模块及阳、阴离子的类型、电荷、尺寸以及晶格扭曲程度等对晶体结构稳定性的影响和相应成相规律。结合荧光材料制备新方法获得单相材料，研究Eu2+、Ce3+等掺杂离子在其中的发光，以及基质组成、结构与发光性能的相互关系，实现对其激发、发射波长的调控、优化其发光效率和稳定性，为探索适合于w-LEDs、PDP和LLP应用的新型高效发光材料奠定理论和实验基础。

新型荧光材料基质的开发及优化具有重要的理论研究与实际应用价值。本项目通过拓展结构矿物学中“类质同象(isomorphism)”取代的思路，从晶体结构的相似性入手探找荧光材料基质，以石榴石、磷灰石和黄长石结构为模型，利用阴离子配位多面体模块调控荧光粉基质晶体结构，进而形成更多的荧光材料基质新物相，并为研究发光特性提供了丰富的空间，获得了一批光色可调型新型稀土发光材料。本项目所完成的代表性工作汇总如下：（1）关于多面体模块构建新型荧光材料基质的方法学研究：以黄长石结构基质Ca2Al(AlSiO7)和Ca2Mg(Si2O7)作为入手点，利用[Al3+–Al3+]对[Ca2+–Mg2+]模块结构单元共取代，构筑了一系列固溶体新物相，结合实验和理论的分析方法，讨论了多面体模块共取代对于基质组分调控的合理性，实现了稀土离子Eu2+在固溶体物相中发光精细调控，解决了单一基质晶格中多组分调变与发光调控的关联性的基础问题。在此基础上，进一步成功推广了多面体模块结构调控方法用于多个发光材料体系的结构构筑。（2）关于多面体模块构建新型荧光材料基质的新体系探索研究：结合本项目提出的结构构筑策略，设计并制备了代表性的石榴石结构Y3Sc2Ga3−xAlxO12:Ce3+、(Lu,Y)3Al5O12:Ce3+和Ca2NaZn2V3O12，磷灰石结构La5(Si2+xB1−x)(O13−xNx):Ce3+和Sr3.45Y6.5O2(PO4)1.5(SiO4)4.5:Eu2+,Mn2+和黄长石结构Ca2Al2Si(O,N)7:Eu2+和CaSrAl2SiO7:Ce3+,Li+,Eu2+等多个系列的稀土发光材料新体系，并实现了发光调控，研究了其在白光LED用光转换荧光粉和长余辉发光材料等领域的应用性能。最后，我们汇总了多面体模块构建新型荧光材料基质和光谱调控的一般性策略，总结性工作已综述的形式分别在Prog. Mater. Sci.（Prog. Mater. Sci., 2016, 84, 59.）和Chem. Soc. Rev.（Chem. Soc. Rev.,2017, 46, 275.）发表。截止到2016年12月，本项目的相关研究内容共发表基金资助密切相关论文35篇，全部被SCI收录；申报国家发明专利5项。培养研究生8名，其中博士研究生1名。本项目圆满完成了任务书中所预定完成的研究成果。