1. SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Building 137, Menlo Park, California 94025, United States
2. Electrical
Engineering Department, Stanford University, 350 Serra Mall, Stanford, California 94305, United States
3. School
of Chemistry and Biochemistry and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, Georgia 30332, United States
4. Department of Materials and Chemistry & Biochemistry, University of California, Santa Barbara, California 93106, United States