Characterization of Light-Emitting Inorganic Nanomaterials using Synchrotron Radiation Spectroscopy

发光材料在光电子学、光学检测、生物医学成像和传感等方面有着广泛的应用。具有所需光学特性的材料通过形态控制、成分调整和表面改性来合成。寻找结构与发光机制之间的联系对于改善光学性质和开发新材料至关重要。同步辐射光谱是一项快速发展的技术，可以提供无法通过实验室技术获得的关键信息。在我提议的研究计划中，我将开发基于同步加速器的表征技术，以深入了解现有和新合成的无机发光材料的发光机制。本文主要采用X射线吸收精细结构（XAFS）和X射线激发光致发光（XEOL）方法。我的研究项目集中在三个主题上，每个主题都有一种类型的材料。主题1.我将研究卤化铅钙钛矿（LHP）的发光机理，并开发具有所需光学性能的LHP的可控合成。利用XAFS-XEOL分析掺杂离子对LHP发光的影响。通过使用纳米探针XEOL和原位XAFS-XEOL监测三元CsxPbyBrz化合物的相变，我将开发策略来调整CsxPbyBrz的相位以实现更高的发光。主题2.我将研究掺杂对生物活性磷酸钙（CaP）的组成和发光的作用。我将研究发光和掺杂的CaP的结构之间的相关性，并开发一种表征技术来跟踪CaP物种的组成演变，使用它们的光学性质。主题3.我将使用XAFS-XEOL分析对金纳米团簇（AuNCs）进行系统的研究，以更深入地了解金属-配体，配体-配体，纳米团簇-细胞相互作用对AuNCs发光的影响。我将设计并进行原位XAFS-XEOL研究，以跟踪Au基Al 2 O3合金NC的形成。明亮的发光AuNCs将基于通过这些获得的基础知识进行设计，并作为新的生物医学传感器和成像剂进行探索。 全世界在建设新的同步加速器设施和更新旧设施方面进行了大量投资。同步加速器光谱学的用户社区已经大大扩展，潜在用户的数量正在急剧增加。使用上述材料作为研究平台，我将开发同步加速器技术，目的是使它们能够被更广泛的社区使用。我将特别注意介绍XAFS+XEOL作为定量材料表征工具的机会，该工具可用于光电子、石化、替代能源、绿色采矿或绿色化学领域的产品开发。

Light-emitting materials have a wide range of applications such as optoelectronics, optical detection, biomedical imaging, and sensing. Materials with desired optical properties are being synthesized through morphology control, composition tuning, and surface modifications. Finding the connection between structure and luminescence mechanism is crucial for improving the optical properties and developing novel materials. Synchrotron radiation spectroscopy is a fast-advancing technology that can provide key information that cannot be obtained through laboratory techniques. In my proposed research program, I will develop synchrotron-based characterization techniques to gain a thorough understanding of the luminescence mechanism in existing and newly synthesized inorganic light-emitting materials. I will use X-ray absorption fine structure (XAFS) and X-ray excited optical luminescence (XEOL) as my primary methods. My research program focuses on three themes, and each featuring one type of material. Theme 1. I will investigate the luminescence mechanism of lead halide perovskite (LHP) and develop controlled synthesis of LHP with desired optical properties. I will apply XAFS-XEOL to analyze the role of doping ions on the luminescence of LHP. By monitoring the phase transformation in a ternary CsxPbyBrz compound using nanoprobe XEOL and in situ XAFS-XEOL, I will develop strategies to tune the phase of CsxPbyBrz to achieve higher luminescence. Theme 2. I will investigate the role of doping on the composition and luminescence of bioactive calcium phosphate (CaP). I will study the correlation between luminescence and the structure of doped CaP, and develop a characterization technique to track composition evolution of CaP species using their optical properties. Theme 3. I will perform a systematic study on gold nanoclusters (AuNCs) using XAFS-XEOL analysis to gain a deeper understanding on how the luminescence of AuNCs are affected by metal-ligand, ligand-ligand, nanocluster-cellular interactions. I will design and perform in situ XAFS-XEOL study to track the formation of Au-based bimetallic alloy NCs. Bright light-emitting AuNCs will be designed based on fundamental knowledge obtained through these, and explored as new biomedical sensors and imaging agents. There has been significant investment worldwide in building new synchrotron facilities and in updating older ones. The synchrotron spectroscopy user community has greatly expanded, and the number of potential users is drastically increasing. Using the materials mentioned above as research platforms, I will develop synchrotron techniques with the aim of making them accessible to a wider community. I will pay particular attention to opportunities for presenting XAFS+XEOL as a quantitative materials characterization tool that may be used for product development by industry in the fields of optoelectronics, petrochemicals, alternative energy, green mining, or green chemistry.