title: Importance of intermolecular interactions in assessing hopping mobilities in organic field effect transistors: pentacene versus dithiophene-tetrathiafulvalene.
abstract: We report on a computational study to understand the high mobility found in dithiophene-tetrathiafulvalene (DT-TTF) transistors, with respect to that known for pentacene, using an extended measure of the reorganization energy (lambdareorg). We demonstrate the high importance of considering intermolecular interactions to assess hole-hopping mobilities. We find that due to the steric, polarizable environment and the structural changes induced by local intermolecular charge delocalization, the calculated lambdareorg for DT-TTF decreases from 0.574 eV in the isolated molecule to 0.042 eV in the crystal embedded molecule, which is of the same order of the previously reported value found for the isolated pentacene molecule, 0.098 eV.
authors.affiliation: Ceramic Membrane Centre, The Pore, DelftChemTech, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands. s.t.bromley@tnw.tudelft.nl
authors.forename: Stefan T
authors.initials: ST
authors.lastname: Bromley
authors.forename: Marta
authors.initials: M
authors.lastname: Mas-Torrent
authors.forename: Peter
authors.initials: P
authors.lastname: Hadley
authors.forename: Concepció
authors.initials: C
authors.lastname: Rovira