稀土纳米结构发光材料在生物医学、新型传感等方面有巨大的应用前景，目前正向多结构组合纳米材料与器件迅猛发展。材料的发光性能依赖于对激发光的吸收情况和发光跃迁速率及量子效率，而光吸收和自发辐射等光跃迁的性能与纳米结构及环境介质密切相关。本项目拟从三个角度开展研究：1）研究单一介质中发光中心的光跃迁性能对介质折射率的依赖，利用实验结果对既有的实腔模型和虚腔模型进行检验；2)在1）的基础上，研究有广泛应用的纳米多层结构中稀土离子光跃迁性能与介质结构和折射率的关系，并对既有理论模型进行必要的扩充和发展；3）探索贵金属-稀土纳米多层复合结构中金属纳米颗粒的尺寸和形貌等参数对发光中心光跃迁性能的调控。通过上述多方面的研究，全面和系统地认识发光中心光跃迁性能对环境介质的依赖关系。期望最终可以通过改变周围环境介质，调控发光中心的光跃迁性能如提高材料的发光效率和发光强度等。

Nanostructure rare-earth doped luminescent materials have great potential application in the fields of biomedicine and sensor materials. The nanophotonic devices with composite structure are becoming a research focus. The luminescent properties of the materials depend on the absorption of excitation light, the lifetime and quantum efficiency of emission etc.. The properties of the optical transitions such as absorption and spontaneous emission are closely related to the surrounding media. This research project focuses on the following three aspects: 1) to carry out experimental study on the dependence of the properties of the optical transitions on the refractive index in homogeneous media, and to test the existing models (virtual-cavity model and real-cavity model); 2) to carry out experimental study on the dependence of optical transitions in composite nanostructures, and to construct theory models for these systems; 3) to explore the dependence of optical properties in noble metal-(rare-earth-doped) insulator composite nanostructures on the size, shape and distance of various composition components. The aim is to gain a comprehensive and systemic understanding of the dependence of the optical properties on the surrounding media. It is expected that the outcome of this research would be important for guiding the design of optical composite nanotructure materials.