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、传感等领域有着广泛的应用。具有所需光学性能的材料正在通过形态控制、成分调节和表面修饰来合成。寻找结构与发光机理之间的联系，对于提高材料的光学性能和开发新材料具有重要意义。同步辐射光谱学是一项快速发展的技术，可以提供实验室技术无法获得的关键信息。在我提出的研究计划中，我将开发基于同步加速器的表征技术，以深入了解现有的和新合成的无机发光材料的发光机理。我将使用X射线吸收精细结构(XAFS)和X射线激发光学发光(XEOL)作为我的主要方法。我的研究计划集中在三个主题上，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的受控合成。我将用XAFS-XEOL来分析掺杂离子对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，我将开发策略来调节CsxPbyBrz的相以获得更高的发光。主题2.我将研究掺杂对生物活性磷酸钙(CAP)的组成和发光的影响。我将研究发光与掺杂帽子结构之间的相关性，并开发一种表征技术，利用其光学性质来跟踪帽子物种的组成演变。主题3.我将利用XAFS-XEOL分析对金纳米团簇(AuNC)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AuNC发光的影响。我将设计并进行原位XAFS-XEOL研究，以跟踪金基双金属合金NCS的形成。明亮发光的AUNCs将基于通过这些技术获得的基础知识来设计，并作为新的生物医学传感器和成像剂进行探索。在建造新的同步加速器设施和更新旧的设施方面，世界各地都进行了大量投资。同步加速器光谱的用户社区已经大大扩大，潜在用户的数量正在急剧增加。利用上面提到的材料作为研究平台，我将开发同步加速器技术，目的是让更广泛的社区能够接触到它们。我将特别注意介绍XAFS+XEOL作为一种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行业产品开发。

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.