1. Department of Medical Engineering, California Institute of Technology (Caltech), 1200 East California Boulevard, Mail Code 136-93, Pasadena, CA 91125, USA.
2. Institute of Microstructure Technology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
3. Light Technology Institute, KIT, Engesserstrasse 13, 76131 Karlsruhe, Germany.
4. Division of Engineering and Applied Sciences, Caltech, Pasadena, CA 91125, USA.
5. Institut für Energie- und Klimaforschung 5 (IEK 5)–Photovoltaik, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.