1. Department of Chemistry and Centre for Plastic Electronics, Imperial College London, London SW7 2AZ, U.K.
2. Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, U.K.
3. Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208-0001, United States
4. Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
5. Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, United States
6. Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506-0055, United States
7. KAUST Solar Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
8. Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
9. Simpson Querrey Institute, Northwestern University, Evanston, Illinois 60611, United States