1. Department of Physics Organic and Carbon Electronics Lab (ORaCEL) North Carolina State University Raleigh NC 27695 USA
2. Department of Chemistry University of North Carolina at Chapel Hill Chapel Hill NC 27599 USA
3. Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing 100190 P. R. China
4. Advanced Light Source Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
5. Advanced Photon Source Argonne National Laboratory Argonne IL 60439 USA