title: Synergistic doping of fullerene electron transport layer and colloidal quantum dot solids enhances solar cell performance.
abstract: The spatial location of the predominant source of performance-limiting recombination in today's best colloidal quantum dot (CQD) cells is identified, pinpointing the TiO2:CQD junction; then, a highly n-doped PCBM layer is introduced at the CQD:TiO2 heterointerface. An n-doped PCBM layer is essential to maintain the depletion region and allow for efficient current extraction, thereby producing a record 8.9% in overall power conversion efficiency.
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada.
authors.forename: Mingjian
authors.initials: M
authors.lastname: Yuan
authors.forename: Oleksandr
authors.initials: O
authors.lastname: Voznyy
authors.forename: David
authors.initials: D
authors.lastname: Zhitomirsky
authors.forename: Pongsakorn
authors.initials: P
authors.lastname: Kanjanaboos
authors.forename: Edward H
authors.initials: EH
authors.lastname: Sargent
keywords: PbS; [6,6]-phenyl-61-butyric acid methyl ester (PCBM); colloidal quantum dots; depleted heterojunctions; photovoltaics