title: 10.6% Certified Colloidal Quantum Dot Solar Cells via Solvent-Polarity-Engineered Halide Passivation.
abstract: Colloidal quantum dot (CQD) solar cells are solution-processed photovoltaics with broad spectral absorption tunability. Major advances in their efficiency have been made via improved CQD surface passivation and device architectures with enhanced charge carrier collection. Herein, we demonstrate a new strategy to improve further the passivation of CQDs starting from the solution phase. A cosolvent system is employed to tune the solvent polarity in order to achieve the solvation of methylammonium iodide (MAI) and the dispersion of hydrophobic PbS CQDs simultaneously in a homogeneous phase, otherwise not achieved in a single solvent. This process enables MAI to access the CQDs to confer improved passivation. This, in turn, allows for efficient charge extraction from a thicker photoactive layer device, leading to a certified solar cell power conversion efficiency of 10.6%, a new certified record in CQD photovoltaics.
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto , 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.
authors.forename: Xinzheng
authors.initials: X
authors.lastname: Lan
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto , 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.
authors.forename: Oleksandr
authors.initials: O
authors.lastname: Voznyy
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto , 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.
authors.forename: F Pelayo
authors.initials: FP
authors.lastname: García de Arquer
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto , 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.
authors.forename: Mengxia
authors.initials: M
authors.lastname: Liu
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto , 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.
authors.forename: Jixian
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto , 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Proppe
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto , 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.
authors.forename: Grant
authors.initials: G
authors.lastname: Walters
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto , 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.
authors.forename: Fengjia
authors.initials: F
authors.lastname: Fan
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto , 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.
authors.forename: Hairen
authors.initials: H
authors.lastname: Tan
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto , 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto , 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto , 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.
authors.forename: Sjoerd
authors.initials: S
authors.lastname: Hoogland
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto , 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.
authors.forename: Edward H
authors.initials: EH
authors.lastname: Sargent
keywords: PbS quantum dots; methylammonium iodide; passivation; solar cells; solvent polarity