LSPR半导体-稀土掺杂氟化物纳米复合材料的可控制备与上转换发光增强的研究

In recent years, using localized surface plasmon resonance（LSPR）effect to enhance the near-infrared excited upconversion luminescence of the rare earth ions have been extensively investigated inspired by their wide potential applications. To date, the mostly used LSPR sources in this aspect are noble metal nanomaterials, but they often induce serious negative effects such as light scattering and re-absorption. To solve these problems, it is necessary to develope new LSPR materials to substitute the noble metals. Aiming this target,this project intends to fabricate and study nanocomposites consisting of the LSPR semiconductor and the rare earth (RE) ions doped fluoride, taking advantage of semiconductor's surface plasmon resonance effect in near-infrared region to enhance the excitation cross section, and therefore the upconversion intensity, of the RE ions. The influence and the related micro-mechanism of the LSPR effect on the RE emissions will be revealed; the relationship between the structure of nanocomposite and the luminescence behavior of RE ions will be established. By modifying the components and microstructures of the nanocomposites, the near-infrared light excited upconversion performance of the RE ions will be improved and optimized. The implementation of this project is expected to result in further enrichment of the synthesis chemistry for functional nanomaterials,the semiconductor photoelectronics, as well as the luminescent physics for the rare earth ions, and lay the foundation for developing novel upconversion materials with excellent properties.

用局域表面等离子体共振（LSPR）效应增强近红外激发的稀土上转换发光是近年来的一个研究热点，应用前景广阔。迄今常用的LSPR源是贵金属纳米材料，但其易带来较强的光散射和再吸收等负作用，且价格昂贵。为此，本项目拟研究用氧族半导体代替贵金属做LSPR源，构建LSPR半导体-稀土掺杂氟化物核-壳纳米复合结构，利用半导体在近红外区的LSPR效应增大氟化物中稀土离子对激发光的吸收截面，进而增强近红外激发的上转换发光。研究液相反应体系中半导体-稀土掺杂氟化物核-壳结构的形成机理与可控制备，以及半导体LSPR特性影响稀土发光的动力学过程和微观机理，建立纳米复合结构-半导体LSPR效应-稀土发光性能之间的关系；在此基础上，通过对纳米复合结构进行调控，优化上转换发光性能。本项目的实施将进一步丰富纳米功能材料合成化学、半导体光电子学和稀土发光物理学，为发展性能优异、成本低廉的新型发光材料奠定基础。

本项目探索并获得了液相制备基于Cu2-xS、ITO、CuGaS2-ZnS等一系列LSPR纳米半导体和稀土掺杂氟化物纳米颗粒的荧光复合材料的实验技术，研究了纳米复合结构的形成机理与可控制备；通过研究分析复合材料的发光性能，揭示了半导体LSPR影响稀土离子能量传递上转换行为的机理和动力学过程；建立了复合结构同荧光性能的关系，并通过调整半导体纳米结构特征来改变LSPR特征吸收波段，从而利用LSPR效应实现了对Er3+、Tm3+等特定稀土离子的特定波段上转换发光的选择性增强，为优化和设计稀土发光特性提供了新的途径。作为项目拓展，还设计合成了一系列性能优异的新型稀土掺杂荧光材料，为稀土荧光材料在荧光传感、白光LED等领域的应用做了有益探索。.项目结果在Adv. Funct. Mater.、Nano Energy、Chem. Mater.、Nanoscale、ACS Appl. Mater. Inter.、J. Mater. Chem. C等国际核心SCI刊物发表论文24篇，其中影响因子大于3的23篇；申请中国发明专利5项（其中已获授权3项）；培养（毕业）硕、博士研究生7名。.本项目的实施进一步丰富了纳米功能材料合成化学、半导体光电子学和稀土发光物理学，为发展具有重要应用前景的新型发光材料奠定了理论与实验基础。