First-principles investigation on the electronic efficiency and binding energy of the contacts formed by graphene and poly-aromatic hydrocarbon anchoring groups
KAUST Grant NumberFIC/2010/08
MetadataShow full item record
Abstract© 2015 AIP Publishing LLC. The electronic efficiency and binding energy of contacts formed between graphene electrodes and poly-aromatic hydrocarbon (PAH) anchoring groups have been investigated by the non-equilibrium Green's function formalism combined with density functional theory. Our calculations show that PAH molecules always bind in the interior and at the edge of graphene in the AB stacking manner, and that the binding energy increases following the increase of the number of carbon and hydrogen atoms constituting the PAH molecule. When we move to analyzing the electronic transport properties of molecular junctions with a six-carbon alkyne chain as the central molecule, the electronic efficiency of the graphene-PAH contacts is found to depend on the energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the corresponding PAH anchoring group, rather than its size. To be specific, the smaller is the HOMO-LUMO gap of the PAH anchoring group, the higher is the electronic efficiency of the graphene-PAH contact. Although the HOMO-LUMO gap of a PAH molecule depends on its specific configuration, PAH molecules with similar atomic structures show a decreasing trend for their HOMO-LUMO gap as the number of fused benzene rings increases. Therefore, graphene-conjugated molecule-graphene junctions with high-binding and high-conducting graphene-PAH contacts can be realized by choosing appropriate PAH anchor groups with a large area and a small HOMO-LUMO gap.
CitationLi Y, Tu X, Wang H, Sanvito S, Hou S (2015) First-principles investigation on the electronic efficiency and binding energy of the contacts formed by graphene and poly-aromatic hydrocarbon anchoring groups. J Chem Phys 142: 164701. Available: http://dx.doi.org/10.1063/1.4918738.
SponsorsThis project was supported by the National Natural Science Foundation of China (No. 61321001) and the MOST of China (Nos. 2011CB933001 and 2013CB933404). S.S. thanks additional funding support from the European Research Council (QUEST project), by KAUST (FIC/2010/08), and by AMBER (12/RC/2278).
JournalThe Journal of Chemical Physics
CollectionsPublications Acknowledging KAUST Support
- Orbital interaction mechanisms of conductance enhancement and rectification by dithiocarboxylate anchoring group.
- Authors: Li Z, Kosov DS
- Issue date: 2006 Oct 5
- The Band Gap of Graphene Is Efficiently Tuned by Monovalent Ions.
- Authors: Colherinhas G, Fileti EE, Chaban VV
- Issue date: 2015 Jan 15
- An orbital rule for electron transport in molecules.
- Authors: Yoshizawa K
- Issue date: 2012 Sep 18
- Electron transport in a pi-stacking molecular chain.
- Authors: Geng WT, Oda M, Nara J, Kondo H, Ohno T
- Issue date: 2008 Mar 13
- Towards a taxonomy of topology for polynuclear aromatic hydrocarbons: linking electronic and molecular structure.
- Authors: Adkins EM, Miller JH
- Issue date: 2017 Oct 25