Abstract
Pyrene, the smallest two-dimensional mesh of aromatic rings, with various terminal thiol substitutions, has been considered as a potential molecular interconnect. Charge transport through two terminal devices has been modeled using density functional theory (with and without self interaction correction) and the non-equilibrium Green's function method. A tetra-substituted pyrene, with dual thiol terminal groups at opposite ends, has been identified as an excellent candidate, owing to its high conductance, virtually independent of bias voltage. The two possible extensions of its motif generate two series of graphene nanoribbons, with zigzag and armchair edges and with semimetallic and semiconducting electron band structure, respectively. The effects related to the wire length and the bias voltage on the charge transport have been investigated for both sets. The conductance of the nanoribbons with a zigzag edge does not show either length or voltage dependence, owing to an almost perfect electron transmission with a continuum of conducting channels. In contrast, for the armchair nanoribbons a slow exponential attenuation of the conductance with the length has been found, due to their semiconducting nature. © 2013 IOP Publishing Ltd.
Original language | English (US) |
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Pages (from-to) | 275301 |
Journal | Journal of Physics: Condensed Matter |
Volume | 25 |
Issue number | 27 |
DOIs | |
State | Published - Jun 14 2013 |
Externally published | Yes |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledged KAUST grant number(s): FIC/2010/08
Acknowledgements: This work was supported by the CSIRO Advanced Materials Transformational Capability Platform. A B thanks CSIRO for support through the Julius Career Award. The use of the NCI National Facility supercomputers at the ANU is gratefully acknowledged. The SMEAGOL project is sponsored by Science Foundation of Ireland (grant no. 07/IN/I945), by KAUST (FIC/2010/08) and by CRANN.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.