1. Molecular
Foundry and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
2. Department
of Chemistry, Columbia University, New York, New York 10027, United States
3. Department
of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea
4. Department
of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, United States
5. Department
of Physics, University of California, Berkeley, California 94720, United States
6. Kavli Energy Nanosciences Institute at Berkeley, Berkeley, California 94720, United States