title: Systematic Analysis of Polymer Molecular Weight Influence on the Organic Photovoltaic Performance.
abstract: The molecular weight of an electron donor-conjugated polymer is as essential as other well-known parameters in the chemical structure of the polymer, such as length and the nature of any side groups (alkyl chains) positioned on the polymeric backbone, as well as their placement, relative strength, the ratio of the donor and acceptor moieties in the backbone of donor-acceptor (D-A)-conjugated polymers, and the arrangement of their energy levels for organic photovoltaic performance. Finding the "optimal" molecular weight for a specific conjugated polymer is an important aspect for the development of novel photovoltaic polymers. Therefore, it is evident that the chemistry of functional conjugated polymers faces major challenges and materials have to adopt a broad range of specifications in order to be established for high photovoltaic performance. In this review, the approaches followed for enhancing the molecular weight of electron-donor polymers are presented in detail, as well as how this influences the optoelectronic properties, charge transport properties, structural conformation, morphology, and the photovoltaic performance of the active layer.
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: Department of Materials Science Engineering, University of Ioannina, Ioannina, 45110, Greece.
authors.forename: Michael
authors.initials: M
authors.lastname: Spanos
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: Christos L
authors.initials: CL
authors.lastname: Chochos
authors.affiliation: Department of Materials Science Engineering, University of Ioannina, Ioannina, 45110, Greece.
authors.forename: Apostolos
authors.initials: A
authors.lastname: Avgeropoulos
mesh_terms: D002384:Catalysis; D011211:Electric Power Supplies; D004563:Electrochemistry; D015394:Molecular Structure; D008970:Molecular Weight; D055668:Photochemical Processes; D058105:Polymerization; D011108:Polymers / Q000737:chemistry; D012993:Solar Energy
chemical_list: D011108:Polymers
keywords: donor-acceptor; molecular weight; organic photovoltaics; polymers