1. Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) and Laboratory for Photovoltaic Energy Conversion, Department of Sustainable Systems Engineering (INATECH), University of Freiburg, Georges-Köhler-Allee 105, Freiburg 79110, Germany
2. Department of General Systems Studies, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan
3. Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
4. Fraunhofer Institute for Solar Energy Systems (ISE), Heidenhofstraße 2, Freiburg 79110, Germany
5. Department of Physics, University of Pavia, Pavia 27100, Italy