title: Beyond Donor-Acceptor (D-A) Approach: Structure-Optoelectronic Properties-Organic Photovoltaic Performance Correlation in New D-A1-D-A2Low-Bandgap Conjugated Polymers.
abstract: Low-bandgap near-infrared polymers are usually synthesized using the common donor-acceptor (D-A) approach. However, recently polymer chemists are introducing more complex chemical concepts for better fine tuning of their optoelectronic properties. Usually these studies are limited to one or two polymer examples in each case study so far, though. In this study, the dependence of optoelectronic and macroscopic (device performance) properties in a series of six new D-A1-D-A2low bandgap semiconducting polymers is reported for the first time. Correlation between the chemical structure of single-component polymer films and their optoelectronic properties has been achieved in terms of absorption maxima, optical bandgap, ionization potential, and electron affinity. Preliminary organic photovoltaic results based on blends of the D-A1-D-A2polymers as the electron donor mixed with the fullerene derivative [6,6]-phenyl-C71-butyric acid methyl ester demonstrate power conversion efficiencies close to 4% with short-circuit current densities (Jsc) of around 11 mA cm-2, high fill factors up to 0.70, and high open-circuit voltages (Vocs) of 0.70 V. All the devices are fabricated in an inverted architecture with the photoactive layer processed in air with doctor blade technique, showing the compatibility with roll-to-roll large-scale manufacturing processes.
authors.affiliation: Department of Materials Science Engineering, University of Ioannina, Ioannina, 45110, Greece.|Advent Technologies SA, Patras Science Park, Stadiou Street, Platani-Rio, Patra, 26504, Greece.
authors.forename: Christos L
authors.initials: CL
authors.lastname: Chochos
authors.affiliation: Department of Materials Science Engineering, University of Ioannina, Ioannina, 45110, Greece.
authors.forename: Sofia
authors.initials: S
authors.lastname: Drakopoulou
authors.affiliation: Department of Materials Science Engineering, University of Ioannina, Ioannina, 45110, Greece.
authors.forename: Athanasios
authors.initials: A
authors.lastname: Katsouras
authors.affiliation: Advent Technologies SA, Patras Science Park, Stadiou Street, Platani-Rio, Patra, 26504, Greece.
authors.forename: Benedetta M
authors.initials: BM
authors.lastname: Squeo
authors.affiliation: Light Technology Institute, Karlsruhe Institute of Technology (KIT), Engesserstrasse 13, 76131, Karlsruhe, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Sprau
authors.affiliation: Light Technology Institute, Karlsruhe Institute of Technology (KIT), Engesserstrasse 13, 76131, Karlsruhe, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Colsmann
authors.affiliation: Advent Technologies SA, Patras Science Park, Stadiou Street, Platani-Rio, Patra, 26504, Greece.|National Hellenic Research Foundation (NHRF), 48 Vassileos Constantinou Avenue, Athens, 11635, Greece.
authors.forename: Vasilis G
authors.initials: VG
authors.lastname: Gregoriou
authors.affiliation: Macromolecular Chemistry Group (buwmakro) and Institute for Polymer Technology, Bergische Universität Wuppertal, Gaußstraße 20, D-42119, Wuppertal, Germany.
authors.forename: Alex-Palma
authors.initials: AP
authors.lastname: Cando
authors.affiliation: Macromolecular Chemistry Group (buwmakro) and Institute for Polymer Technology, Bergische Universität Wuppertal, Gaußstraße 20, D-42119, Wuppertal, Germany.
authors.forename: Sybille
authors.initials: S
authors.lastname: Allard
authors.affiliation: Macromolecular Chemistry Group (buwmakro) and Institute for Polymer Technology, Bergische Universität Wuppertal, Gaußstraße 20, D-42119, Wuppertal, Germany.
authors.forename: Ullrich
authors.initials: U
authors.lastname: Scherf
authors.affiliation: Institute of Materials for Electronics and Energy Technology (I-MEET), Friedrich-Alexander-University Erlangen-Nuremberg, Martensstraße 7, 91058, Erlangen, Germany.
authors.forename: Nicola
authors.initials: N
authors.lastname: Gasparini
authors.affiliation: Institute of Materials for Electronics and Energy Technology (I-MEET), Friedrich-Alexander-University Erlangen-Nuremberg, Martensstraße 7, 91058, Erlangen, Germany.
authors.forename: Negar
authors.initials: N
authors.lastname: Kazerouni
authors.affiliation: Institute of Materials for Electronics and Energy Technology (I-MEET), Friedrich-Alexander-University Erlangen-Nuremberg, Martensstraße 7, 91058, Erlangen, Germany.
authors.forename: Tayebeh
authors.initials: T
authors.lastname: Ameri
authors.affiliation: Institute of Materials for Electronics and Energy Technology (I-MEET), Friedrich-Alexander-University Erlangen-Nuremberg, Martensstraße 7, 91058, Erlangen, Germany.|Bavarian Center for Applied Energy Research (ZAE Bayern), Haberstrasse 2a, 91058, Erlangen, Germany.
authors.forename: Christoph J
authors.initials: CJ
authors.lastname: Brabec
authors.affiliation: Department of Materials Science Engineering, University of Ioannina, Ioannina, 45110, Greece.
authors.forename: Apostolos
authors.initials: A
authors.lastname: Avgeropoulos
mesh_terms: D011211:Electric Power Supplies; D015394:Molecular Structure; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D012993:Solar Energy
chemical_list: D011108:Polymers
keywords: conjugated polymers; donor-acceptor; low bandgap; near-infrared; organic photovoltaics