1. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
2. College of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
3. Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
4. Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
5. Department of Materials Science & Engineering, University of California, Berkeley, Berkeley, California 94720, United States
6. Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States