1. Department of Applied Physics Stanford University Stanford CA 94305 USA
2. Department of Materials Science and Engineering Stanford University Stanford CA 94305 USA
3. Commonwealth Scientific and Industrial Research Organisation (CSIRO) Manufacturing Bayview Avenue Clayton VIC 3168 Australia
4. Energy Research Institute@NTU Nanyang Technological University Nanyang Avenue Singapore 639798
5. School of Materials Science and Engineering Nanyang Technological University Nanyang Avenue Singapore 639798
6. Department of Chemistry and Biochemistry Worcester Polytechnic Institute Worcester MA 01609 USA
7. Materials Physics and Application Division Los Alamos National Laboratory Los Alamos NM 87545 USA
8. Laboratory of Photonics and Interfaces Institute of Chemical Sciences and Engineering École Polytechnique Fédérale de Lausanne Lausanne CH‐1015 Switzerland