title: Rational Design of High-Performance Wide-Bandgap (≈2 eV) Polymer Semiconductors as Electron Donors in Organic Photovoltaics Exhibiting High Open Circuit Voltages (≈1 V).
abstract: Systematic optimization of the chemical structure of wide-bandgap (≈2.0 eV) "donor-acceptor" copolymers consisting of indacenodithiophene or indacenodithieno[3,2-b]thiophene as the electron-rich unit and thieno[3,4-c]pyrrole-4,6-dione as the electron-deficient moiety in terms of alkyl side chain engineering and distance of the electron-rich and electron-deficient monomers within the repeat unit of the polymer chain results in high-performance electron donor materials for organic photovoltaics. Specifically, preliminary results demonstrate extremely high open circuit voltages (Vocs) of ≈1.0 V, reasonable short circuit current density (Jsc) of around 11 mA cm-2, and moderate fill factors resulting in efficiencies close to 6%. All the devices are fabricated in an inverted architecture with the photoactive layer processed by doctor blade equipment, showing the compatibility with roll-to-roll large-scale manufacturing processes. From the correlation of the chemical structure-optoelectronic properties-photovoltaic performance, a rational guide toward further optimization of the chemical structure in this family of copolymers, has been achieved.
authors.affiliation: Department of Materials Science Engineering, University of Ioannina, Ioannina, 45110, 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: Athanasios
authors.initials: A
authors.lastname: Katsouras
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: Department of Materials Science Engineering, University of Ioannina, Ioannina, 45110, Greece.
authors.forename: Chrysanthos
authors.initials: C
authors.lastname: Koulogiannis
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: D055664:Electrochemical Techniques; D004583:Electrons; D015394:Molecular Structure; D055668:Photochemical Processes; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D011789:Quantum Theory; D012666:Semiconductors
chemical_list: D011108:Polymers
keywords: high open circuit voltage; indacenodithiophene; organic photovoltaics; ternary solar cells; wide-bandgap conjugated polymers