title: Switchable supramolecular assemblies on graphene.
abstract: We studied the self-assembly of trimesic acid on single- and few-layer graphene supported by SiO2 substrates. A scanning tunneling microscope operated under ambient conditions was utilized to image supramolecular networks of trimesic acid at liquid-graphene interfaces. Trimesic acid can self-assemble into large-scale, highly ordered adlayers on graphene surfaces. Phase transition of the trimesic acid adlayer from a close-packed structure to a porous chicken-wire structure was observed by changing from single- to few-layer graphene, which was attributed to the modulation of molecule-graphene interactions by the layer number of graphene. The guest-induced phase transition of trimesic acid by complexation with coronene on single-layer graphene further confirms that supramolecular networks on graphene can be rationally tailored with sub-nanometer resolution by balancing between intermolecular vs. molecule-graphene interactions. We further investigated the effects of trimesic acid adlayers on the electronic transport properties of graphene transistors. The adsorption of trimesic acid induces p-doping and defects in the adlayers cause scattering of charge carriers in single-layer graphene.
authors.affiliation: National Center for Nanoscience and Technology, 11 Beiyitiao Street, Zhongguancun, Beijing 100190, China. Fangy@nanoctr.cn Wangch@nanoctr.cn.
authors.forename: Qiaoyu
authors.initials: Q
authors.lastname: Zhou
authors.forename: Yibao
authors.initials: Y
authors.lastname: Li
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Yibing
authors.initials: Y
authors.lastname: Wang
authors.forename: Yanlian
authors.initials: Y
authors.lastname: Yang
authors.forename: Ying
authors.initials: Y
authors.lastname: Fang
authors.forename: Chen
authors.initials: C
authors.lastname: Wang