1. Friedrich Schiller Universität Jena, Institut
für Festkörperphysik, Helmholtzweg 5, 07743 Jena, Germany
2. Department
of Chemistry and Biochemistry, The University of Arizona, 1306 East
University Boulevard, Tucson, Arizona 85721, United States
3. School
of Chemistry and Biochemistry and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
4. National Renewable Energy Laboratory, Golden, Colorado 80401, United States
5. Solar and
Photovoltaics Engineering Research Center, King Abdullah University of Science and Technology−KAUST, Thuwal 23955-6900, Kingdom of Saudi Arabia