1. Department of Electrical and Computer Engineering; University of Toronto; 10 King's College Road Toronto Ontario M5S 3G4 Canada
2. Department of Materials Science and Engineering; University of Toronto; 184 College Street Toronto Ontario M5S 3E4 Canada
3. Division of Physical Sciences and Engineering; Solar and Photovoltaics Engineering Center; King Abdullah University of Science and Technology (KAUST); Thuwal 23955-6900 Saudi Arabia