title: Electron-Deficient Dihydroindaceno-Dithiophene Regioisomers for n-Type Organic Field-Effect Transistors.
abstract: In this work, we wish to report the first member of a new family of organic semiconductors constructed on a meta dihydroindacenodithiophene core, that is, 2,2'-(2,8-dihexyl-4,6-dihydro-s-indaceno[1,2-b:7,6-b']dithiophene-4,6-diylidene)dimalononitrile (called meta-IDT(═C(CN)2)2). The properties of this molecule were studied in detail through a structure-properties relationship study with its regioisomer, that is, 2,2'-(2,7-dihexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b']dithiophene-4,9-diylidene)dimalononitrile (para-IDT(═C(CN)2)2) (see isomer structures in blue in Chart 2). The influence of the bridge functionalization was also investigated by comparison with their diketone analogues meta-IDT(═O)2and para-IDT(═O)2. This study sheds light on the impact of regioisomerism on the electronic properties at the molecular level (electrochemistry, absorption spectroscopy, molecular modeling) and also on the supramolecular arrangement, and finally on the organic field-effect transistors (OFET) performances and stabilities. The significant effect of self-assembled monolayers of 4-(dimethylamino)benzenethiol grafted on the gold drain and source electrodes or of the use of flexible substrate (polyethylene naphtalate) instead of glass on the OFET performances and stabilities are also reported. In the light of these results (maximum mobility reaching 7.1 × 10-2cm2V-1cm-1, high IDon/IDoffof 2.3 × 107, and subthreshold swing of 1.2 V/dec), we believe that the present OFETs can be further used to construct electronic circuits.
authors.affiliation: Institut des Sciences Chimiques de Rennes, Équipe Matière Condensée et Systèmes Électroactifs, UMR CNRS 6226 , Bât.10C, Campus de Beaulieu, 35042 Rennes cedex, France.
authors.forename: Jean-David
authors.initials: JD
authors.lastname: Peltier
authors.affiliation: Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, CNRS-Université de Strasbourg , 23 rue du Loess, BP 43, 67034 Strasbourg Cedex 2, France.
authors.forename: Benoît
authors.initials: B
authors.lastname: Heinrich
authors.affiliation: Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, CNRS-Université de Strasbourg , 23 rue du Loess, BP 43, 67034 Strasbourg Cedex 2, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Donnio
authors.affiliation: Institut des Sciences Chimiques de Rennes, Équipe Matière Condensée et Systèmes Électroactifs, UMR CNRS 6226 , Bât.10C, Campus de Beaulieu, 35042 Rennes cedex, France.
authors.forename: Joëlle
authors.identifier: http://orcid.org/0000-0001-6738-8749
authors.initials: J
authors.lastname: Rault-Berthelot
authors.affiliation: Institut d'Électronique et des Télécommunications de Rennes, Département Microélectronique & Microcapteurs, UMR CNRS 6164 , Bât.11B, Université Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Jacques
authors.affiliation: Institut des Sciences Chimiques de Rennes, Équipe Matière Condensée et Systèmes Électroactifs, UMR CNRS 6226 , Bât.10C, Campus de Beaulieu, 35042 Rennes cedex, France.
authors.forename: Cyril
authors.identifier: http://orcid.org/0000-0002-6036-1778
authors.initials: C
authors.lastname: Poriel
keywords: FET mobility; dihydroindaceno−dithiophene; flexible electronics; metal−semiconductor interface; organic field-effect transistor; organic semiconductors