1. Department of Electrical and Systems Engineering, Department of Materials Science and Engineering, and Department of Chemistry, University of Pennsylvania, 200 South 33rd Street, Philadelphia, PA 19104, USA.
2. Schulich Faculty of Chemistry, Solid State Institute and Russell Berrie Nanotechnology Institute, Technion, Haifa 32000, Israel.
3. Department of Electrical and Computer Engineering, 10 King’s College Rd, Toronto ON M5S 3G4, Canada.
4. Department of Chemistry and James Franck Institute, University of Chicago, Chicago, IL 60637, USA.
5. Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL 60439, USA.