HZB and TU Berlin: New joint research group at BESSY II
Prof. Birgit Kanngießer heads a joint research group on X-ray methods, which is funded by TU Berlin and HZB. © Martin Weinhold
Birgit Kanngießer is setting up a joint research group to combine X-ray methods in laboratories and at large-scale facilities. In particular, the physicist wants to investigate how X-ray experiments on smaller laboratory instruments can be optimally complemented with more complex experiments that are only possible at synchrotron sources such as BESSY II.
Prof. Dr. Birgit Kanngießer is professor of analytical X-ray Physics at the Technische Universität Berlin, where she also heads a large research group. Together with the Max Born Institute she has build up BLiX (Berlin laboratory for innovative X-ray technologies), which brings established X-ray methods from the synchrotron into the laboratory. At BESSY II she was involved as one of the first users from the early on.
Now HZB and TU Berlin are funding a joint research group headed by Birgit Kanngießer to strengthen this cooperation. This should also accelerate the exchange of knowledge and technology between BESSY II and university laboratories.
The joint research group is called 'Combined X-ray methods at BLiX and BESSY II - SyncLab'. On the TU Berlin side, the Berlin laboratory for innovative X-ray technologies (BLiX) is integrated. Kanngießer will initially focus on evaluating how time-resolved measurements using near-edge X-ray spectroscopy in the soft X-ray range on smaller instruments and at BESSY II could complement each other. Further analytical and imaging X-ray methods are to follow in the future.
- Disorder creates new properties in compound semiconductorsAn international research team has demonstrated that the intrinsic disorder of the compound semiconductor CuInSnS₄ can be exploited to influence its optical properties. While the atomic vibrations also sense the local disorder, their response is averaged over many different local environments and therefore appear isotropic, as expected for a cubic crystal. In contrast, the optical excitations, known as excitons, are much more sensitive to the local arrangement of atoms. Surprisingly, they show a direction-dependent optical response even though the average crystal structure is cubic. These findings shed new light on the relationship between disorder and material properties, opening up new options for targeted 'disorder engineering' in optoelectronic and photocatalytic devices.
- Perovskite solar cells: Predictions of long-term stabilityReliable statements about the long-term stability of perovskite solar cells are still difficult to make. However, a new study by Dr Carolin Ulbrich’s team, published in the renowned journal Joule, highlights which methods are useful for this purpose and identifies areas where further research is needed.
- Superconducting TES array X-ray spectrometer goes into operation at BESSY IIEurope's first and only TES-spectrometer at a synchrotron source is now in operation at BESSY II, developed within a collaboration between the HZB, the MPI-CEC (Mühlheim-an-der-Ruhr, Germany) and the NIST (Boulder CO, USA). The photon detection efficiency of the new instrument exceeds that of wavelength-dispersive X-ray emission spectrometers by a factor of 100 to 1000. It will be used to investigate the electronic properties of atomically thin layers, nanostructures and highly diluted atomic and molecular samples. The team is looking forward to receiving exciting research proposals from the user community.