1. Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, Bern CH-3012, Switzerland
2. Adolphe Merkle Institute, Chemin des Verdiers 4, Fribourg CH-1700, Switzerland
3. Helmholtz Young Investigator Group FRONTRUNNER, IEK5-Photovoltaics, Forschungszentrum Jülich, Jülich 52428, Germany
4. Institute for Photovoltaics, University of Stuttgart, Stuttgart 70569, Germany