title: The relationship between nanoscale architecture and charge transport in conjugated nanocrystals bridged by multichromophoric Polymers.
abstract: We report on the self-assembly and the electrical characterization of bicomponent films consisting of an organic semiconducting small molecule blended with a rigid polymeric scaffold functionalized in the side chains with monomeric units of the same molecule. The molecule and polymer are a perylene-bis(dicarboximide) monomer (M-PDI) and a perylene-bis(dicarboximide)-functionalized poly(isocyanopeptide) (P-PDI), which have been codeposited on SiO(x) and mica substrates from solution. These bicomponent films have been characterized by atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM), revealing the relationship between architecture and function for various supramolecular nanocrystalline arrangements at a nanometer spatial resolution. Monomer-polymer interactions can be controlled by varying solvent and/or substrate polarity, so that either the monomer packing dictates the polymer morphology or vice versa, leading to a morphology exhibiting M-PDI nanocrystals connected with each other by P-PDI polymer wires. Compared to pure M-PDI or P-PDI films, those bicomponent films that possess polymer interconnections between crystallites of the monomer display a significant improvement in electrical connectivity and a 2 orders of magnitude increase in charge carrier mobility within the film, as measured in thin film transistor (TFT) devices. Of a more fundamental interest, our technique allows the bridging of semiconducting crystals, without the formation of injection barriers at the connection points.
authors.affiliation: Instituto per la Sintesi Organica e la Fotoreattivita-Consiglio Nazionale delle Ricerche, Via Gobetti 101, I-40129 Bologna, Italy.
authors.forename: Reza
authors.initials: R
authors.lastname: Dabirian
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Palermo
authors.forename: Andrea
authors.initials: A
authors.lastname: Liscio
authors.forename: Erik
authors.initials: E
authors.lastname: Schwartz
authors.forename: Matthijs B J
authors.initials: MB
authors.lastname: Otten
authors.forename: Chris E
authors.initials: CE
authors.lastname: Finlayson
authors.forename: Emanuele
authors.initials: E
authors.lastname: Treossi
authors.forename: Richard H
authors.initials: RH
authors.lastname: Friend
authors.forename: Gianluca
authors.initials: G
authors.lastname: Calestani
authors.forename: Klaus
authors.initials: K
authors.lastname: Müllen
authors.forename: Roeland J M
authors.initials: RJ
authors.lastname: Nolte
authors.forename: Alan E
authors.initials: AE
authors.lastname: Rowan
authors.forename: Paolo
authors.initials: P
authors.lastname: Samorì