Electronic transport in biphenyl single-molecule junctions with carbon nanotubes electrodes: The role of molecular conformation and chirality

Journal Article · Sun Aug 15 00:00:00 EDT 2010 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.82.085402· OSTI ID:21421403

Brito Silva, Jr, C A; Granhen, E R ^[1]; Leal, J F. P. ^[2]; Del Nero, J ^[3]; Pinheiro, F A ^[4]

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1. Pos-Graduacao em Engenharia Eletrica, Universidade Federal do Para, 66075-900 Belem, PA (Brazil)
2. Pos-Graduacao em Fisica, Universidade Federal do Para, 66075-110 Belem, PA (Brazil)
3. Departamento de Fisica, Universidade Federal do Para, 66075-110 Belem, PA (Brazil)
4. Instituto de Fisica, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro, RJ (Brazil)

We investigate, by means of ab initio calculations, electronic transport in molecular junctions composed of a biphenyl molecule attached to metallic carbon nanotubes. We find that the conductance is proportional to cos{sup 2} {theta}, with {theta} the angle between phenyl rings, when the Fermi level of the contacts lies within the frontier molecular orbitals energy gap. This result, which agrees with experiments in biphenyl junctions with nonorganic contacts, suggests that the cos{sup 2} {theta} law has a more general applicability, irrespective of the nature of the electrodes. We calculate the geometrical degree of chirality of the junction, which only depends on the atomic positions, and demonstrate that it is not only proportional to cos{sup 2} {theta} but also is strongly correlated with the current through the system. These results indicate that molecular conformation plays the preponderant role in determining transport properties of biphenyl-carbon nanotubes molecular junctions.

• OSTI ID: 21421403
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 82, Issue 8; Other Information: DOI: 10.1103/PhysRevB.82.085402; (c) 2010 The American Physical Society; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BIPHENYL
CARBON
CARRIER MOBILITY
CHIRALITY
ENERGY GAP
FERMI LEVEL
MOLECULES
NANOTUBES
AROMATICS
ELEMENTS
ENERGY LEVELS
HYDROCARBONS
MOBILITY
NANOSTRUCTURES
NONMETALS
ORGANIC COMPOUNDS
PARTICLE PROPERTIES