First-principles investigation of the structural and electronic properties of self-assemblies of functional molecules on graphene. (May 2017)

• Record Type: Journal Article
• Authors: Quesne-Turin, Ambroise; Touzeau, Jeremy; Dappe, Yannick J.; Diawara, Boubakar; Maurel, François; Seydou, Mahamadou
• Is Part Of: Superlattices and microstructures. Volume 105(2017)
• Page Start: 139
• Page End: 151
• Publication Date: 2017-05
• Subjects: Self-assembly -- Graphene -- Supramolecular network -- DFT -- Adsorption -- Hydrogen bonds -- DOS; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2017.03.034
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: Graphene-based two-dimensional materials have attracted an increasing attention these last years. Among them, the system formed by molecular adsorption on, aim of modifying the conductivity of graphene and make it semiconducting, is of particular interest. We use here hierarchical first-principles simulations to investigate the energetic and electronic properties of an electron-donor, melamine, and an acceptor, NaphtaleneTetraCarboxylic DiImide (NTCDI), and the assembly of their complexes on graphene surface. In particular, the van der Waals-corrected density functional theory (DFT) method is used to compute the interaction and adsorption energies during assembly. The effect of dispersion interactions on both geometries and energies is investigated. Depending on the surface coverage and the molecular organization, there is a significant local deformation of the graphene surface. Self-assembly is driven by the competition between hydrogen bonds in the building blocks and their adsorption on the surface. The dispersion contribution accounts significantly in both intermolecular and adsorption energies. The electron transfer mechanism and density of states (DOS) calculations show the electron-donor and acceptor characters of melamine and NTCDI, respectively. Molecular adsorption affects differently the energy levels around the Fermi level differently, leading to band gap opening. These results provide information about the new materials obtained by controlling molecular assembly on graphene. Graphical abstract: Highlights: Melamine and NTCDI assembly investigated on graphene sheet at different coverage. Adsorption of melamine shows an important deformation of graphene accompanied by charge transfer. Dispersion play a significant role in adsorption energies. Different doping characters observed for the two functional molecules. Band gap opening up to 100 meV observed when molecules are adsorbed on graphene.