First-principles investigation on the electronic efficiency and binding energy of the contacts formed by graphene and poly-aromatic hydrocarbon anchoring groups

Handle URI:
http://hdl.handle.net/10754/598335
Title:
First-principles investigation on the electronic efficiency and binding energy of the contacts formed by graphene and poly-aromatic hydrocarbon anchoring groups
Authors:
Li, Yang; Tu, Xingchen; Wang, Hao; Sanvito, Stefano; Hou, Shimin
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.
Citation:
Li 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.
Publisher:
AIP Publishing
Journal:
The Journal of Chemical Physics
KAUST Grant Number:
FIC/2010/08
Issue Date:
28-Apr-2015
DOI:
10.1063/1.4918738
PubMed ID:
25933778
Type:
Article
ISSN:
0021-9606; 1089-7690
Sponsors:
This 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).
Appears in Collections:
Publications Acknowledging KAUST Support

Full metadata record

DC FieldValue Language
dc.contributor.authorLi, Yangen
dc.contributor.authorTu, Xingchenen
dc.contributor.authorWang, Haoen
dc.contributor.authorSanvito, Stefanoen
dc.contributor.authorHou, Shiminen
dc.date.accessioned2016-02-25T13:18:55Zen
dc.date.available2016-02-25T13:18:55Zen
dc.date.issued2015-04-28en
dc.identifier.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.en
dc.identifier.issn0021-9606en
dc.identifier.issn1089-7690en
dc.identifier.pmid25933778en
dc.identifier.doi10.1063/1.4918738en
dc.identifier.urihttp://hdl.handle.net/10754/598335en
dc.description.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.en
dc.description.sponsorshipThis 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).en
dc.publisherAIP Publishingen
dc.titleFirst-principles investigation on the electronic efficiency and binding energy of the contacts formed by graphene and poly-aromatic hydrocarbon anchoring groupsen
dc.typeArticleen
dc.identifier.journalThe Journal of Chemical Physicsen
dc.contributor.institutionCentre for Nanoscale Science and Technology, Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, Chinaen
dc.contributor.institutionSchool of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2, Irelanden
kaust.grant.numberFIC/2010/08en

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