1. Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstrasse 2, 79110 Freiburg, Germany
2. Department of Sustainable Systems Engineering (INATECH), University of Freiburg, Emmy-Noether-Strasse 2, 79108 Freiburg, Germany
3. Cluster of Excellence livMatS@FIT-Freiburg Center for Interactive Materials and Bioinspired Technologies, University Freiburg, Georges-Kohler-Allee 105, 79110 Freiburg,Germany