1. Department of Chemical and Biomolecular Engineering, University of California Berkeley, Berkeley, California 94720, United States
2. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
3. Department of Physics, University of California Berkeley, Berkeley, California 94720, United States
4. Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
5. Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
6. Kavli Energy NanoSciences Institute at Berkeley, Berkeley, California 94720, United States