1. Department of Chemistry, University of California, Berkeley, California 94720, USA
2. Kavli Energy NanoScience Institute,
Berkeley, California 94720, USA
3. Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720,
USA
4. Chemical Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720,
USA
5. Department of Physics, University of California, Berkeley, California 94720, USA
6. STROBE NSF Science & Technology Center, University of California, Berkeley, California 94720, USA