1. King Abdullah University of Science and Technology (KAUST), KAUST Solar
Center (KSC), and Physical Science
and Engineering Division (PSE), Thuwal 23955-6900, Saudi Arabia
2. Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 3G4, Canada
3. School
of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, Georgia 30332-0400, United States