掺Yb3+近红外下转换发光材料的能量传递机制的研究

项目名称： 掺Yb3+近红外下转换发光材料的能量传递机制的研究

项目编号： No.11274038

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 由芳田

作者单位： 北京交通大学

项目金额： 90万元

中文摘要： 近年来稀土下转换发光材料，特别是掺Yb3+的量子剪裁材料，因有可能提高太阳能电池的效率而成为国内外的研究热点。通过一个Tb3+、Pr3+或Er3+等离子到两个Yb3+离子的能量传递，实现可见光到近红外光的转换，并且量子效率高于100%。但对于能量传递机制目前存在很大争议，而能量传递机制直接决定量子效率的计算方法，影响对材料性能的判断。由于能量传递机制取决于能量给体和受体的能级位置，本申请拟以确定稀土离子的基态相对于基质的价带和导带的能级位置为主，结合光谱信息和衰减特性，从实验和理论两方面深入研究不同基质中双掺离子之间的能量传递或电子转移过程。虽然稀土离子能级结构的理论已经十分成熟，但对于不同的基质中这些能级相对于基质能带的位置尚未形成完整、清晰的认识，因此有必要进行相关研究，为设计稀土下转换发光材料并正确评估其性能，提供实验和理论的依据。

中文关键词： 能量传递；稀土离子；下转换；近红外；衰减曲线

英文摘要： Recently luminescent materials doped with rare earth ions, especially the Yb3+-doped quantum cutting materials, have attracted a great interest for photovoltaic application to improve solar cell efficiency. Energy transfer from one Tb3+ (Pr3+ or Er3+) ion to two or more Yb3+ ions results in the downconversion of a visible photon into two near infrared (NIR) photons, the quantum efficiency is higher than 100%. However, there are several different mechanisms for the energy transfer process. The judgment of the material properties may be wrong when an uncorrect method is used to calculate the quantum efficiency which depends on what happened during the energy transfer process. The aim of this project is to elucidate the energy transfer mechanisms for the couple ions in different hosts. The energy level positions of both the donor and the acceptor determine the energy transfer mechanism, so we plan to firstly study the location of the ground states of the rare earth ions relative to the valence band and conduction band of the host materials. In addition, emission spectra, excitation spectra and the luminescence decay curves will be investigated. In comparison with the quantum efficiency derived from the experimental evidence, the energy transfer process and the electron transfer process will be analyzed on the basis

英文关键词： Energy transfer；Rare earth ions；Downconversion；NIR；Decay curves