1. Department
of Electrical and Computer Engineering, University of Toronto, 10 King’s College Road, Toronto, Ontario M5S 3G4, Canada
2. Department
of Chemistry and Nano Science, Ewha Womans University, 52, Ewhayeodae-gil,
Seodaemun-gu, Seoul 03760, Korea
3. King Abdullah University of Science and Technology (KAUST), Solar and Photovoltaic Engineering Research Center, and Physical Sciences and Engineering Division, Thuwal 23955-6900, Saudi Arabia