1. Department of Chemistry Stanford University Stanford CA 94305 USA
2. Department of Physics University of California Berkeley Berkeley CA 94720 USA
3. Materials Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
4. Stanford Institute for Materials and Energy Sciences SLAC National Accelerator Laboratory Menlo Park CA 94025 USA
5. Department of Geological Sciences Stanford University Stanford CA 94305 USA
6. Kavli Energy NanoScience Institute University of California Berkeley Berkeley CA 94720 USA