Tuning Molecular Assembly of Pentacene via Surface Modification of Substrates

MasterIncorporation graphene and conjugated molecules is expected to be solution for flexible electronic devices. While graphene is a promising material for being electrodes, its influences on conjugated molecules’ arrangements and morphologies, which are known very important to devices’ performances, are still ambiguous. Due to polymer contaminants on graphene’s surface from transfer process, growth behaviors of organic semiconducting materials on it could not be well extracted. This paper presents a novel approach to fabricate clean areas of graphene’s surface without exploiting organic solvent or special equipment. Using this method, correlation between pentacene structure on the graphene’s surface and supporting substrates’ surfaces energies is clarified. The results reveal interesting phenomenon of pentacene’s behaviors on graphene. While its crystallography, which majorly expresses (020) plane, is determined only by the graphene’s surface, growth modes, nucleation densities and islands’ heights are strongly affected by the graphene’s supporting surfaces energies. Thus, without any chemical or physical modification, only tuning graphene’s supporting substrates can control morphology of adsorbed molecules on top. This work presents here has profound implications for future studies of graphene’s template effect which is vital in organic electronic field