A German research team has developed a tandem solar cell that reaches 24 percent efficiency—measured according to the fraction of photons converted into electricity (i.e., electrons). This sets a new world record as the highest efficiency achieved so far with this combination of organic and perovskite-based absorbers. The solar cell was developed by Professor Dr. Thomas Riedl's group at the University of Wuppertal together with researchers from the Institute of Physical Chemistry at the University of Cologne and other project partners from the Universities of Potsdam and Tübingen as well as the Helmholtz-Zentrum Berlin and the Max-Planck-Institut für Eisenforschng in Düsseldorf. The results have been published in Nature under the title "Perovskite–organic tandem solar cells with indium oxide interconnect."