1. Materials Sciences Division, Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
2. Department of Chemistry, University of California, Berkeley, CA 94720, USA.
3. Nanoscale Physics Research Laboratory, School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
4. National Center for Electron Microscopy, Molecular Foundry, Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
5. Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USA.
6. Department of Physics, University of Washington, Seattle, WA 98195, USA.
7. Miller Research Institute, University of California Berkeley, Berkeley, CA 94720, USA.
8. Kavli Energy NanoScience Institute, Berkeley, CA 94720, USA.