1. Department of Materials Science and Engineering, University of California, Irvine, California 92697, United States
2. Nanoscience Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
3. Department of Chemistry, University of California, Irvine, California 92697, United States
4. Department of Physics and Astronomy, University of California, Irvine, California 92697, United States
5. Department of Chemical and Biomolecular Engineering, University of California, Irvine, California 92697, United States