BR50: How Berlin could be developed into a world-leading science metropolis

Perovskite semiconductors efficiently convert sunlight into electrical energy; they are also inexpensive and extremely lightweight. A team at HZB has developed a triple-junction solar cell comprising different perovskite semiconductors, with a novel bilayer of graphene oxide (GO) and a self-assembled monolayer (SAM) as the hole conductor. This bilayer significantly increases both efficiency and long-term stability. The efficiency of the novel perovskite triple-junction solar cell is 27.3% and shows hardly any decline even after more than 770 hours of operation. The study has been published in the renowned journal Joule.

End of June, the Ukraine Recovery Conference (UCR2026) took place in Gdańsk, Poland. Unlike previous editions, URC2026 introduced a dedicated Energy Platform, jointly organised by the Ministry of Energy of Ukraine and the Ministry of Climate and Environment of Poland, which brought together energy-related discussions, announcements, and side events in one place, increasing the visibility and coordination of key energy topics. Green Deal Ukraїna, an initiative coordinated by HZB, organised three events on the sidelines of URC on research and energy topics as part of the conference.

Materials 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.