20 Years Russian-German Joint Laboratory at BESSY II
To mark its 20th anniversary, the Russian-German Laboratory at the BESSY II storage ring for synchrotron radiation in Berlin is organising an online workshop on 18 and 19 November. Scientists will discuss the future perspectives of Russian-German cooperation as well as innovative projects and new goals of the laboratory.
Since its foundation two decades ago, numerous scientists from Russia and Germany have worked at the Russian-German Joint Laboratory and have since published around 770 publications. The research cooperation is now supported by eight partner organisations - Freie Universität Berlin, Helmholtz-Zentrum Berlin, Technische Universität Dresden and Technische Universität Bergakademie Freiberg. They are joined by St. Petersburg State University, the Ioffe Institute in St. Petersburg and the Kurchatov Institute and Shubnikov Institute of Crystallography in Moscow.
The laboratory receives funding from the Federal Ministry of Education and Research. Messreisen supports the HZB and the German-Russian Centre of Excellence G-RISC, which is funded by the German Academic Exchange Service (DAAD) with funds from the Federal Foreign Office.
The researchers will use the anniversary workshop to discuss current highlights from their research. Expert lectures will deal with the magnetism of two-dimensional crystals, i.e. novel materials that can make the computer hardware of the future more powerful and energy-efficient, as well as new battery materials and the question of why novel materials for solar cells show unexpectedly high efficiency. "What does the future hold for the Russian-German Laboratory?" asks Eckart Rühl, Professor of Physical Chemistry at the Free University of Berlin and coordinator of the research laboratory. New synchrotron radiation sources are already being planned in Germany and Russia, he says. "BESSY II will continue to provide excellent opportunities for the Russian-German Laboratory in the coming decade. And the planned successor source BESSY III will make previously unfeasible experiments possible!" emphasises Prof. Dr. Jan Lüning, scientific director of Helmholtz-Zentrum Berlin.
Program of the Workshop on 18 and 19 November 2021
- CIGS-perovskite tandem cell achieves record efficiency of 25.5 %A Berlin-based team from HZB and Center for the Science of Materials Berlin (CSMB) at the Humboldt-Universität zu Berlin has set a new record for a tandem solar cell. Using a combination of a CIGS semiconductor layer and perovskite, along with several optimised intermediate layers, they were able to convert 25.5% of sunlight into electrical energy. The previous record for this combination of materials and this size of cell stood at 24.6%. The new record has been certified and is visible in the prestigious Solar Cell Efficiency Tables (the "Green Tables"), which serve as the definitive ledger for the global photovoltaic community.
- 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.
- 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.