title: Mimicking conjugated polymer thin-film photophysics with a well-defined triblock copolymer in solution.
abstract: Conjugated polymers (CPs) are promising materials for use in electronic applications, such as low-cost, easily processed organic photovoltaic (OPV) devices. Improving OPV efficiencies is hindered by a lack of a fundamental understanding of the photophysics in CP-based thin films that is complicated by their heterogeneous nanoscale morphologies. Here, we report on a poly(3-hexylthiophene)-block-poly(tert-butyl acrylate)-block-poly(3-hexylthiophene) rod-coil-rod triblock copolymer. In good solvents, this polymer resembles solutions of P3HT; however, upon the addition of a poor solvent, the two P3HT chains within the triblock copolymer collapse, affording a material with electronic spectra identical to those of a thin film of P3HT. Using this new system as a model for thin films of P3HT, we can attribute the low fluorescence quantum yield of films to the presence of a charge-transfer state, providing fundamental insights into the condensed phase photophysics that will help to guide the development of the next generation of materials for OPVs.
authors.affiliation: Center for Nano and Molecular Science and Technology and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA. johanna.brazard@cea.fr
authors.forename: Johanna
authors.initials: J
authors.lastname: Brazard
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Ono
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Bielawski
authors.forename: Paul F
authors.initials: PF
authors.lastname: Barbara
authors.forename: David A
authors.initials: DA
authors.lastname: Vanden Bout