1. Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
2. Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92037, USA
3. Université de Strasbourg, CNRS, ICS UPR 22, F-67000 Strasbourg, France
4. Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
5. Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
6. pi-Conjugated Polymers Unit, Okinawa Institute of Science and Technology, Onna, Okinawa 904-0495, Japan
7. Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA