Poster award for HZB PhD student
John Uhlrich, Editor-in-Chief at Wiley VCH presented an award to Quentin Jeangros, EPFL, and Eike Köhnen, HZB, for their outstanding posters (from left to right). © Gruppe Steve Albrecht/HZB
Eike Köhnen received an award for his poster on perovskite silicon tandem cells at the 4th International Conference on Perovskite Solar Cells and Optoelectronics (PSCO) in Lausanne, Switzerland. He is a PhD student in the Junior Research Group on Perovskite Tandem Cells led by Dr. Steve Albrecht.
Tandem cells made of organometallic perovskite layers and silicon have the potential for very high efficiencies. While perovskites in particular convert blue parts of the light spectrum into electrical energy, silicon uses the red parts of the light. Eike Köhnen is working on the design of a so-called monolithic tandem cell.
For his poster, which he presented at the 4th International Conference on Perovskite Solar Cells and Optoelectronics (PSCO) in Lausanne, Switzerland, he received an award sponsored by Wiley Science Publishers.
Köhnen has realized a highly efficient monolithic tandem solar cell with an efficiency of 25 percent, which has also been certified by independent bodies. The tandem cell was manufactured at HZB, the silicon cell being produced at HZB-Institute PVcomB and the perovskite cell at HySPRINT. By optimizing the optical and electrical properties of the tandem-top contact, it was even possible to achieve an efficiency of 26 percent, which is the highest efficiency currently published in the literature for this tandem architecture. Since the spectrum arriving on Earth changes over the course of the day, Köhnen also investigated the influence of the spectrum on the behavior of the tandem solar cell.
- Lithium-sulphur batteries with lean electrolyte: problem areas clarifiedUsing a non-destructive method, a team at HZB investigated practical lithium-sulphur pouch cells with lean electrolyte for the first time. With operando neutron tomography, they could visualise in real-time how the liquid electrolyte distributes and wets the electrodes across multilayers during charging and discharging. These findings offer valuable insights into the cell failure mechanisms and are helpful to design compact Li-S batteries with a high energy density in formats relevant to industrial applications.
- Self assembling monolayer can improve lead-free perovskite solar cells tooTin perovskite solar cells are not only non-toxic, but also potentially more stable than lead-containing perovskite solar cells. However, they are also significantly less efficient. Now, an international team has succeeded in reducing losses in the lower contact layer of tin perovskite solar cells: The scienstists identified chemical compounds that self-assemble into a molecular layer that fits very well with the lattice structure of tin perovskites. On this monolayer, tin perovskite with excellent optoelectronic quality can be grown, which increases the performance of the solar cell.
- Berlin Science Award goes to Philipp AdelhelmBattery researcher Prof. Dr. Philipp Adelhelm has been awarded the 2024 Berlin Science Award. He is a professor at the Institute of Chemistry at Humboldt University in Berlin (HU) and heads a joint research group at HU and the Helmholtz Zentrum Berlin (HZB). The materials scientist and electrochemist is investigating sustainable batteries, which play a key role in the success of the energy transition. He is one of the leading international experts in the field of sodium-ion batteries.