1. Joint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, California 91125, United States
2. Materials Science Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
3. Thomas J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California 91125, United States
4. Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
5. Department of Physics, University of California, Berkeley, Berkeley, California 94720, United States
6. Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
7. Kavli Energy NanoSciences Institute, University of California, Berkeley, Berkeley, California 94720, United States