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.
- Long-term stability for perovskite solar cells: a big step forwardPerovskite solar cells are inexpensive to produce and generate a high amount of electric power per surface area. However, they are not yet stable enough, losing efficiency more rapidly than the silicon market standard. Now, an international team led by Prof. Dr. Antonio Abate has dramatically increased their stability by applying a novel coating to the interface between the surface of the perovskite and the top contact layer. This has even boosted efficiency to almost 27%, which represents the state-of-the-art. After 1,200 hours of continuous operation under standard illumination, no decrease in efficiency was observed. The study involved research teams from China, Italy, Switzerland and Germany and has been published in Nature Photonics.
- Two precision mechanics from HZB are Berlin's best traineesTwo former apprentices from the HZB workshop have achieved something remarkable: Fiete Buchin and Edgar Lunk completed their training as precision mechanics, taking first and second place in all of Berlin. In this interview, they share what it took to reach the top, what makes their training special, and the advice they would give to future apprentices.
- Successful master's degree in IR thermography on solar facadesWe are delighted to congratulate our student employee Luca Raschke on successfully completing her Master's degree in Renewable Energies at the Hochschule für Technik und Wirtschaft Berlin - and with distinction!