Laboratory-based X-ray Absorption Spectrometer

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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.