1. Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
2. Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
3. Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208, United States
4. Hummingbird Scientific, USA, Lacey, Washington 98516, United States
5. Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States