1. Department of Materials Science and Engineering, University of California, Irvine, Irvine, California 92697, United States
2. Department of Chemical and Biomolecular Engineering, University of California, Irvine, Irvine, California 92697, United States
3. Department of Physics, University of California, Davis, Davis, California 95616, United States
4. Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States