1. Department
of Materials Science and Engineering, Stanford University, Stanford, California United States
2. Institut
für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden, Germany
3. School
of Chemistry and Biochemistry and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332-0400, United States
4. Materials & Devices Advanced Research Institute, LG Electronics, 38 Baumoe-ro, Seocho-gu, Seoul 137-724, Korea
5. Department
of Chemistry and Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506-0055, United States
6. Solar and
Photovoltaics Engineering Research Center, Physical Science and Engineering
Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia