1. Department of Chemistry University of Illinois at Urbana‐Champaign Urbana IL 61801 USA
2. Department of Materials Science and Engineering Frederick Seitz Materials Research Laboratory University of Illinois at Urbana‐Champaign Urbana IL 61801 USA
3. Department of Electronic Engineering Tsinghua University Beijing 100084 China
4. Division of Engineering and Applied Sciences California Institute of Technology Pasadena CA 91125 USA
5. J. A. Woollam Co., Inc Lincoln NE 68508 USA
6. Integrated Nanotechnology Lab CEMSE Division King Abdullah University of Science and Technology (KAUST) Thuwal 23955 Saudi Arabia
7. The Joint Center for Artificial Photosynthesis California Institute of Technology Pasadena CA 91125 USA
8. Kavli Nanoscience Institute California Institute of Technology Pasadena CA 91125 USA
9. Division of Chemistry and Chemical Engineering Beckman Institute California Institute of Technology Pasadena CA 91125 USA