title: Reducing the efficiency-stability-cost gap of organic photovoltaics with highly efficient and stable small molecule acceptor ternary solar cells.
abstract: Technological deployment of organic photovoltaic modules requires improvements in device light-conversion efficiency and stability while keeping material costs low. Here we demonstrate highly efficient and stable solar cells using a ternary approach, wherein two non-fullerene acceptors are combined with both a scalable and affordable donor polymer, poly(3-hexylthiophene) (P3HT), and a high-efficiency, low-bandgap polymer in a single-layer bulk-heterojunction device. The addition of a strongly absorbing small molecule acceptor into a P3HT-based non-fullerene blend increases the device efficiency up to 7.7 ± 0.1% without any solvent additives. The improvement is assigned to changes in microstructure that reduce charge recombination and increase the photovoltage, and to improved light harvesting across the visible region. The stability of P3HT-based devices in ambient conditions is also significantly improved relative to polymer:fullerene devices. Combined with a low-bandgap donor polymer (PBDTTT-EFT, also known as PCE10), the two mixed acceptors also lead to solar cells with 11.0 ± 0.4% efficiency and a high open-circuit voltage of 1.03 ± 0.01 V.
authors.affiliation: Department of Chemistry and Centre for Plastic Electronics, Imperial College London, London SW7 2AZ, UK.|King Abdullah University of Science and Technology (KAUST), KSC, Thuwal 23955-6900, Saudi Arabia.|IEK5-Photovoltaics, Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: Derya
authors.initials: D
authors.lastname: Baran
authors.affiliation: Department of Chemistry and Centre for Plastic Electronics, Imperial College London, London SW7 2AZ, UK.|King Abdullah University of Science and Technology (KAUST), KSC, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Raja Shahid
authors.identifier: 0000-0003-1885-2271
authors.initials: RS
authors.lastname: Ashraf
authors.affiliation: Department of Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, California 94305, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Hanifi
authors.affiliation: King Abdullah University of Science and Technology (KAUST), KSC, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Maged
authors.initials: M
authors.lastname: Abdelsamie
authors.affiliation: Institute of Materials for Electronics and Energy Technology (I-MEET), Friedrich-Alexander-University Erlangen-Nuremberg, 91058 Erlangen, Germany.
authors.forename: Nicola
authors.initials: N
authors.lastname: Gasparini
authors.affiliation: Department of Physics and Center of Plastic Electronics, Imperial College London, London SW7 2AZ, UK.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Röhr
authors.affiliation: Department of Chemistry and Centre for Plastic Electronics, Imperial College London, London SW7 2AZ, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Holliday
authors.affiliation: Department of Chemistry and Centre for Plastic Electronics, Imperial College London, London SW7 2AZ, UK.
authors.forename: Andrew
authors.identifier: 0000-0002-9050-0599
authors.initials: A
authors.lastname: Wadsworth
authors.affiliation: Department of Chemistry and Centre for Plastic Electronics, Imperial College London, London SW7 2AZ, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Lockett
authors.affiliation: King Abdullah University of Science and Technology (KAUST), KSC, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Marios
authors.initials: M
authors.lastname: Neophytou
authors.affiliation: Department of Physics and Center of Plastic Electronics, Imperial College London, London SW7 2AZ, UK.|Grantham Institute for Climate Change and the Environment, Imperial College London, London SW7 2AZ, UK.
authors.forename: Christopher J M
authors.initials: CJ
authors.lastname: Emmott
authors.affiliation: Department of Physics and Center of Plastic Electronics, Imperial College London, London SW7 2AZ, UK.|Grantham Institute for Climate Change and the Environment, Imperial College London, London SW7 2AZ, UK.
authors.forename: Jenny
authors.identifier: 0000-0003-1048-1330
authors.initials: J
authors.lastname: Nelson
authors.affiliation: Institute of Materials for Electronics and Energy Technology (I-MEET), Friedrich-Alexander-University Erlangen-Nuremberg, 91058 Erlangen, Germany.
authors.forename: Christoph J
authors.initials: CJ
authors.lastname: Brabec
authors.affiliation: King Abdullah University of Science and Technology (KAUST), KSC, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Aram
authors.initials: A
authors.lastname: Amassian
authors.affiliation: Department of Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, California 94305, USA.
authors.forename: Alberto
authors.initials: A
authors.lastname: Salleo
authors.affiliation: IEK5-Photovoltaics, Forschungszentrum Jülich, 52425 Jülich, Germany.|Faculty of Engineering and CENIDE, University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kirchartz
authors.affiliation: Department of Chemistry and Centre for Plastic Electronics, Imperial College London, London SW7 2AZ, UK.
authors.forename: James R
authors.initials: JR
authors.lastname: Durrant
authors.affiliation: Department of Chemistry and Centre for Plastic Electronics, Imperial College London, London SW7 2AZ, UK.|King Abdullah University of Science and Technology (KAUST), KSC, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Iain
authors.initials: I
authors.lastname: McCulloch