title: Anisotropic Conjugated Polymer Chain Conformation Tailors the Energy Migration in Nanofibers.
abstract: Conjugated polymers are complex multichromophore systems, with emission properties strongly dependent on the electronic energy transfer through active subunits. Although the packing of the conjugated chains in the solid state is known to be a key factor to tailor the electronic energy transfer and the resulting optical properties, most of the current solution-based processing methods do not allow for effectively controlling the molecular order, thus making the full unveiling of energy transfer mechanisms very complex. Here we report on conjugated polymer fibers with tailored internal molecular order, leading to a significant enhancement of the emission quantum yield. Steady state and femtosecond time-resolved polarized spectroscopies evidence that excitation is directed toward those chromophores oriented along the fiber axis, on a typical time scale of picoseconds. These aligned and more extended chromophores, resulting from the high stretching rate and electric field applied during the fiber spinning process, lead to improved emission properties. Conjugated polymer fibers are relevant to develop optoelectronic plastic devices with enhanced and anisotropic properties.
authors.affiliation: Istituto Nanoscienze-CNR, Euromediterranean Center for Nanomaterial Modelling and Technology (ECMT) , via Arnesano, I-73100 Lecce, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Camposeo
authors.affiliation: Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States.
authors.forename: Ryan D
authors.initials: RD
authors.lastname: Pensack
authors.affiliation: Istituto Nanoscienze-CNR, Euromediterranean Center for Nanomaterial Modelling and Technology (ECMT) , via Arnesano, I-73100 Lecce, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Moffa
authors.affiliation: Dipartimento di Matematica e Fisica "Ennio De Giorgi", Università del Salento , via Arnesano, I-73100 Lecce, Italy.
authors.forename: Vito
authors.initials: V
authors.lastname: Fasano
authors.affiliation: Istituto di Cristallografia (IC-CNR) , via Amendola 122/O, I-70126 Bari, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Altamura
authors.affiliation: Istituto di Cristallografia (IC-CNR) , via Amendola 122/O, I-70126 Bari, Italy.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Giannini
authors.affiliation: Istituto Nanoscienze-CNR, Euromediterranean Center for Nanomaterial Modelling and Technology (ECMT) , via Arnesano, I-73100 Lecce, Italy.|Dipartimento di Matematica e Fisica "Ennio De Giorgi", Università del Salento , via Arnesano, I-73100 Lecce, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Pisignano
authors.affiliation: Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Scholes