dc.contributor.author | SANVITO, STEFANO | en |
dc.date.accessioned | 2015-06-09T11:47:06Z | |
dc.date.available | 2015-06-09T11:47:06Z | |
dc.date.issued | 2015 | en |
dc.date.submitted | 2015 | en |
dc.identifier.citation | Li, Y. Tu, X. Wang, H. Sanvito, S. Hou, S., First-principles investigation on the electronic efficiency and binding energy of the contacts formed by graphene and poly-aromatic hydrocarbon anchoring groups, Journal of Chemical Physics, 142, 16, 2015, 164701- | en |
dc.identifier.other | Y | en |
dc.identifier.uri | http://hdl.handle.net/2262/74022 | |
dc.description | PUBLISHED | en |
dc.description.abstract | The electronic e
ffi
ciency 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 e
ffi
ciency
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 correspond-
ing 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 e
ffi
ciency 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.sponsorship | 164701-7 Li
et al.
J. Chem. Phys.
142
, 164701 (2015)
increase of the number of fused benzene rings. Therefore,
graphene-molecule-graphene junctions with high-binding and
high-conducting graphene-PAH contacts can be constructed
by choosing appropriate PAH anchoring groups with a large
area and a small HOMO-LUMO gap. These findings will help
the design of molecular devices with graphene electrodes.
It should be noted that the energy barrier for these PAH
molecules to displace from the AB stacking configuration is
comparable with the thermal energy K
B
T at room temperature
(0.025 eV). Thus, these PAH molecules are mobile over
the graphene surface at room temperature.
45
PAH-graphene
contacts with high thermal stability may be fabricated by
attaching suitable side groups onto the PAH molecules, an
aspect requiring further investigations in the future.
ACKNOWLEDGMENTS
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). | en |
dc.format.extent | 164701 | en |
dc.relation.ispartofseries | Journal of Chemical Physics | en |
dc.relation.ispartofseries | 142 | en |
dc.relation.ispartofseries | 16 | en |
dc.rights | Y | en |
dc.subject | HOMO-LUMO gap | en |
dc.subject.lcsh | HOMO-LUMO gap | en |
dc.title | First-principles investigation on the electronic efficiency and binding energy of the contacts formed by graphene and poly-aromatic hydrocarbon anchoring groups | en |
dc.type | Journal Article | en |
dc.type.supercollection | scholarly_publications | en |
dc.type.supercollection | refereed_publications | en |
dc.identifier.peoplefinderurl | http://people.tcd.ie/sanvitos | en |
dc.identifier.rssinternalid | 103986 | en |
dc.identifier.doi | http://dx.doi.org/10.1063/1.4918738 | en |
dc.rights.ecaccessrights | openAccess | |
dc.identifier.rssuri | http://www.scopus.com/inward/record.url?eid=2-s2.0-84928481935&partnerID=40&md5=a7987e52a3e80c4d0adfd6471b924548 | en |