1. Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Göteborg, Sweden
2. Physical Chemistry, University of Saarland, Saarbrücken 66123, Germany
3. Georgia Institute of Technology, School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Atlanta, Georgia 30332-0400, United States
4. Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado 80303, United States
5. Laboratory of Organic Electronics, Linköping University, 60174 Norrköping, Sweden
6. Departments of Chemical and Biological Engineering and of Chemistry, University of Colorado Boulder, Boulder, Colorado 80303, United States