title: Light-enhanced liquid-phase exfoliation and current photoswitching in graphene-azobenzene composites.
abstract: Multifunctional materials can be engineered by combining multiple chemical components, each conferring a well-defined function to the ensemble. Graphene is at the centre of an ever-growing research effort due to its combination of unique properties. Here we show that the large conformational change associated with the trans-cis photochemical isomerization of alkyl-substituted azobenzenes can be used to improve the efficiency of liquid-phase exfoliation of graphite, with the photochromic molecules acting as dispersion-stabilizing agents. We also demonstrate reversible photo-modulated current in two-terminal devices based on graphene-azobenzene composites. We assign this tuneable electrical characteristics to the intercalation of the azobenzene between adjacent graphene layers and the resulting increase in the interlayer distance on (photo)switching from the linear trans-form to the bulky cis-form of the photochromes. These findings pave the way to the development of new optically controlled memories for light-assisted programming and high-sensitive photosensors.
authors.affiliation: Nanochemistry Laboratory, ISIS &icFRC, Université de Strasbourg &CNRS, 8 allée Gaspard Monge, 67000 Strasbourg, France.
authors.forename: Markus
authors.initials: M
authors.lastname: Döbbelin
authors.affiliation: Nanochemistry Laboratory, ISIS &icFRC, Université de Strasbourg &CNRS, 8 allée Gaspard Monge, 67000 Strasbourg, France.
authors.forename: Artur
authors.initials: A
authors.lastname: Ciesielski
authors.affiliation: Nanochemistry Laboratory, ISIS &icFRC, Université de Strasbourg &CNRS, 8 allée Gaspard Monge, 67000 Strasbourg, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Haar
authors.affiliation: Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, B-7000 Mons, Belgium.
authors.forename: Silvio
authors.initials: S
authors.lastname: Osella
authors.affiliation: Cambridge Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 OFA, UK.
authors.forename: Matteo
authors.initials: M
authors.lastname: Bruna
authors.affiliation: Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, B-7000 Mons, Belgium.
authors.forename: Andrea
authors.initials: A
authors.lastname: Minoia
authors.affiliation: Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, B-7000 Mons, Belgium.
authors.forename: Luca
authors.initials: L
authors.lastname: Grisanti
authors.affiliation: Nanochemistry Laboratory, ISIS &icFRC, Université de Strasbourg &CNRS, 8 allée Gaspard Monge, 67000 Strasbourg, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Mosciatti
authors.affiliation: Nanochemistry Laboratory, ISIS &icFRC, Université de Strasbourg &CNRS, 8 allée Gaspard Monge, 67000 Strasbourg, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: Richard
authors.affiliation: Laboratory of Supramolecular Biomaterials and Chemistry, ISIS &icFRC, Université de Strasbourg &CNRS, 8 allée Gaspard Monge, 67000 Strasbourg, France.
authors.forename: Eko Adi
authors.initials: EA
authors.lastname: Prasetyanto
authors.affiliation: Laboratory of Supramolecular Biomaterials and Chemistry, ISIS &icFRC, Université de Strasbourg &CNRS, 8 allée Gaspard Monge, 67000 Strasbourg, France.
authors.forename: Luisa
authors.initials: L
authors.lastname: De Cola
authors.affiliation: ISOF-CNR, via Gobetti 101, 40129 Bologna, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Palermo
authors.affiliation: IMM-CNR Sezione di Bologna, via Gobetti, 101, 40129 Bologna, Italy.|Dipartimento di Chimica 'G. Ciamician', Università di Bologna, via Selmi 2, 40126 Bologna, Italy.
authors.forename: Raffaello
authors.initials: R
authors.lastname: Mazzaro
authors.affiliation: IMM-CNR Sezione di Bologna, via Gobetti, 101, 40129 Bologna, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Morandi
authors.affiliation: Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, B-7000 Mons, Belgium.
authors.forename: Roberto
authors.initials: R
authors.lastname: Lazzaroni
authors.affiliation: Cambridge Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 OFA, UK.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Ferrari
authors.affiliation: Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, B-7000 Mons, Belgium.
authors.forename: David
authors.initials: D
authors.lastname: Beljonne
authors.affiliation: Nanochemistry Laboratory, ISIS &icFRC, Université de Strasbourg &CNRS, 8 allée Gaspard Monge, 67000 Strasbourg, France.
authors.forename: Paolo
authors.initials: P
authors.lastname: Samorì