Laboratory-based X-ray Absorption Spectrometer

x射线吸收光谱（XAS）能够研究复杂材料系统中元素特定的原子尺度结构，并提供与x射线衍射或电子显微镜等其他技术所获得的结构信息高度互补的结构信息。目前，这些测量几乎完全是在同步辐射源上进行的，因为它们需要可变能量和高强度的单色x射线。然而，进入这些大型设施受到限制，规划和执行实验需要很长时间。然而，由于最新的技术进步，第一批基于实验室的XAS光谱仪现在可以在商业上使用。因此，2019年初被任命为莱比锡大学正教授的申请人计划建立一个XAS实验室，作为她新成立的小组的核心实验设施，并将所申请的光谱仪作为基石。申请人和她的团队多年来一直在深入应用XAS来研究复杂半导体中局部元素特定结构与重要材料特性之间的相关性。一台功能强大、用途广泛的实验室XAS光谱仪将能够确定黄铜矿、kesterites和其他硫族化合物的原子尺度结构，这些化合物被用作高效薄膜太阳能电池或热电材料的吸收剂，但也可以用于其他有前途的材料系统，如基于cu的半导体，这些材料系统在DFG研究单元FOR 2857的框架内进行了研究。除了在众多研究项目和合作中的应用外，该光谱仪还将用于在国际层面上推进目前基于实验室的XAS的技术和方法发展。通过系统地评估光谱仪在实际研究应用中的能力和局限性，将提出进一步发展的新方法。已经计划以低温样品环境的形式对光谱仪进行第一次扩展，这是目前应用的一部分。此外，基于实验室的XAS光谱仪提供了向学生更容易地介绍XAS的可能性，使他们参与到最先进的分析技术中，从而为研究型教学提供宝贵的动力。因此，不仅在同步加速器上进行XAS测量，而且在小组自己的实验室现场进行XAS测量的能力对于莱比锡大学这个新小组的成功建立，发展和未来工作是绝对必要的。

X-ray absorption spectroscopy (XAS) enables the investigation of the element-specific atomic-scale structure of complex material systems and provides structural information highly complementary to that obtained by other techniques such as X-ray diffraction or electron microscopy. Currently, the measurements are performed almost exclusively at synchrotron radiation sources since they require monochromatic X-rays of variable energy and high intensity. The access to these large-scale facilities is restricted though and long time scales arise for planning and performing experiments. Thanks to the most recent technological progress, however, the first laboratory-based XAS spectrometers are now available commercially. Therefore, the applicant, who was appointed full professor at the University of Leipzig at the beginning of 2019, plans to build a XAS Laboratory as core experimental facility of her newly founded group with the requested spectrometer as the foundation stone.The applicant and her group have already applied XAS intensively for many years to investigate the correlation between local element-specific structure and important material properties in complex semiconductors. A powerful and versatile laboratory-based XAS spectrometer will enable the determination of the atomic-scale structure of chalcopyrites, kesterites and other chalcogenides, used as absorbers in high-efficiency thin film solar cells or as thermoelectrics, but also of other promising material systems such as CuI-based semiconductors, which are investigated in the framework of the DFG Research Unit FOR 2857. Apart from the application in numerous research projects and collaborations, the spectrometer will be used to advance the current technical and methodical development of laboratory-based XAS on an international level. By systematically evaluating the capabilities and limitations of the spectrometer in real-life research applications, new approaches for further developments will be proposed. A first extension of the spectrometer in the form of a cryogenic sample environment is already planned and part of the present application. Moreover, a laboratory-based XAS spectrometer provides the possibility to introduce students much more readily to XAS, to involve them in state-of-the-art analytical techniques and thus to provide valuable impulses for a research-oriented teaching. The capability to perform XAS measurements not only at a synchrotron but also on site in the group’s own laboratory is therefore absolutely essential for the successful establishment, growth and future work of this new group at the University of Leipzig.