1. Center for Polymers and Organic Solids University of California Santa Barbara CA 93106 USA
2. Institute of Physics and Astronomy University of Potsdam 14476 Potsdam Germany
3. Department of Physics and Organic and Carbon Electronics Lab (ORaCEL) North Carolina State University Raleigh NC 27695 USA
4. Helmholtz‐Zentrum Berlin für Materialien und Energie GmbH Institut für Silizium Photovoltaik Kekuléstr. 5 12489 Berlin Germany
5. Mitsubishi Chemical Center for Advanced Materials University of California Santa Barbara CA 93106 USA