Only a few years ago, solar cells made of perovskite materials with efficiencies of around 10 % achieved only a meager energy yield. Today, the latest cells impress with an efficiency more than twice as high. Research groups at the HZB have been instrumental in this rapid and significant improvement of cell characteristics. This novel tandem solar cell consists of a silicon cell and a second, superimposed cell based on a semiconductor compound with perovskite structure. The advantage of combining different materials: their absorption spectra complement each other. This means that tandem solar cells can significantly exceed the physical limit of 29.4 percent efficiency of the silicon solar cells used today.
Now the scientists at HZB want to go one step further. The goal of Prof. Dr. Bernd Stannowski from the Photovoltaics PVcomB Competence Center at HZB is to increase the efficiency of such cells by more than 30 % - not only on a laboratory scale, but also when produced on a commercial scale. The researchers are relying on modular systems that will raise the production of silicon-perowskite tandem solar cells to an industry-relevant level. This will make it possible to produce tandem cells on 6-inch wafers, as is common in the photovoltaic industry.