On 16 May 2022, HZB received a delegation from the Brazilian Ministry of Research, Technology, and Innovation.
© K. Fuchs / HZB
A high-ranking Brazilian delegation visited HZB
© K. Fuchs / HZB
© K. Fuchs / HZB
© K. Fuchs / HZB
© K. Fuchs / HZB
© K. Fuchs / HZB
© K. Fuchs / HZB
© K. Fuchs / HZB
© K. Fuchs / HZB
On 16 May 2022, HZB received a delegation from the Brazilian Ministry of Science, Technology and Innovation (MCTI). Vice-Minister of Science Sergio Freitas de Almeida was visibly impressed by the many research activities being done at HZB to drive the transition to a climate-neutral energy supply in society forward.
The delegation visited HZB in advance of the 9th German–Brazilian Dialogue on Science, taking place from 17 to 20 May 2022 in Berlin. Vice-Minister Sergio Freitas de Almeida was accompanied by State Secretaries José Gontijo (Entrepreneurship and Innovation) and Marcelo Morales (Research and Scientific Training) along with other government representatives.
The delegation toured the X-ray source BESSY II which, of course, is also available to Brazilian researchers. The energy research laboratory EMIL and the new research platform for catalysis research CatLab were also on the tour programme. New catalysts are a key component for producing green hydrogen efficiently and cost-effectively, as well as alternative, sustainable fuels and green raw materials for the chemical industry. The interest of the Brazilian delegation in the development of hydrogen technologies was very high. They were also very interested in cooperation between their light source SIRIUS in Campinas (Sao Paolo) and BESSY II in Berlin.
The discussions with representatives of the Brazilian government inspired all participants to strengthen cooperation in the area of research.
- Magnetic imaging: Micro-flowers increase the local magnetic fieldMaterials with magnetic nanostructures have many potential applications such as in spintronics. To explore such materials, nanoscale magnetic-sensitive imaging techniques are very useful, but up to now only weak magnetic fields could be applied during the imaging process. Now an international collaboration led by Dr. Sergio Valencia, HZB, has developed an approach that overcomes this limitation. The team designed tiny magnetic flux concentrators (MFCs), into which the sample is placed. The geometry of the MFCs resembles a flower with a number of petals which focus the applied magnetic field into its center. This greatly expands the magnetic field range available during imaging, and so the range of magnetic systems that can be investigated. The micro-flowers, enhancing magnetic fields locally, can find application in different nanometric magnetic microscopy techniques.
- 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.