HZB to participate in two Clusters of Excellence
Scientists at the Helmholtz-Zentrum Berlin (HZB) are researching novel systems of materials that can convert or store energy. The HZB will now also be contributing this expertise to the "MATH+" and "UniSysCat" Excellence Clusters being coordinated by Berlin universities. Over the next three years, the Helmholtz Association will fund HZB's participation under the Helmholtz Excellence Network with a total of 1.8 million euros.
Prof. Christiane Becker, who heads the Nanooptics Group at HZB in the Renewable Energies division, is involved in the "MATH+" Excellence Cluster. Becker investigates and develops optoelectronic materials with nanoscale features for solar cells and sensors and cooperates closely with mathematicians in MATH+. Their common goal is the development of highly efficient next-generation solar energy technologies, such as improved light management in tandem perovskite-silicon solar cells, for example. They will also work together on hybrid components for the production of solar fuels and develop simulation and optimisation methods.
MATH+ partner
MATH+ is the short name for "Forschungszentrum der Berliner Mathematik / Berlin Mathematics Research Center". The Freie Universität Berlin, Humboldt-Universität zu Berlin and Technische Universität Berlin as well as the Weierstrass Institute for Applied Analysis and Stochastics and the Zuse Institute Berlin are all participating in this project. The Helmholtz Association will fund HZB's participation with 800,000 euros from the Helmholtz Initiative and Networking Fund over the next three years.
UniSysCat: Focus on catalysis
Researchers in the "UniSysCat" (Unifying Systems in Catalysis) Excellence Cluster are developing complex catalytic systems. They focus on catalytic processes that are activated by sunlight. “These processes make it possible to use sunlight for generation of chemical fuels as well as for high energy-density compounds in a sustainable way. A particular challenge here is to link the rapid absorption processes in semiconductor materials with the often much slower electrochemical reactions of the bound catalyst“, explains Prof. Roel van de Krol, head of the HZB Institute for Solar Fuels. The HZB is contributing its particular expertise in material synthesis of thin-film absorbers, photoelectrochemistry, and time-resolved optical spectroscopy.
UniSysCat partner
UniSysCat is being coordinated by the Technische Universität Berlin. In addition, teams from Freie Universität Berlin, Humboldt-Universität zu Berlin, the University of Potsdam, Charité Universitätsmedizin Berlin, Fritz Haber Institute, Max Planck Institute of Colloids and Interfaces (MPIKG), and the Leibniz Institute for Molecular Pharmacology (FMP) are also participating. The Helmholtz Association will fund the HZB‘s participation with 1 million euros over the next three years from the Helmholtz Initiative and Networking Fund.
- 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.
- 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.