Role of contact bonding on electronic transport in metal–carbon nanotube–metal systems

We have investigated the effects of the interfacial bond arrangement on the electronic transport features of metal–nanotube–metal systems. The transport properties of finite, defect-free armchair and zigzag single-walled carbon nanotubes attached to Au(111) metallic contacts have been calculated by means of the non-equilibrium Green functional formalism with the tight-binding and the extended Huckel Hamiltonians. Our calculations show that the electrode material is not the only factor which rules contact transparency. Indeed, for the same electrode, but changing nanotube helicities, we have observed an overall complex behaviour of the transmission spectra due to band mixing and interference. A comparison of the two models shows that the tight-binding approach fails to give a satisfactory representation of the transmission function when a more accurate description of the C–C and Au–C chemical bonds has to be considered. We have furthermore examined the effect of interface geometry variance on conduction and found that the contact–nanotube distance has a significant impact, while the contact–nanotube symmetry plays a marginal, yet evident role.

[1]  J. Pople,et al.  Approximate Self-Consistent Molecular Orbital Theory. I. Invariant Procedures , 1965 .

[2]  Electrostatic potential profiles of molecular conductors , 2004, cond-mat/0401605.

[3]  E. Anderson,et al.  Scanned probe microscopy of electronic transport in carbon nanotubes. , 2000, Physical review letters.

[4]  Benedict,et al.  Quantum conductance of carbon nanotubes with defects. , 1996, Physical review. B, Condensed matter.

[5]  Noel S. Hush,et al.  Formalism, analytical model, and a priori Green's-function-based calculations of the current-voltage characteristics of molecular wires , 2000 .

[6]  C. Dekker,et al.  Logic Circuits with Carbon Nanotube Transistors , 2001, Science.

[7]  M. Anantram,et al.  Effect of scattering and contacts on current and electrostatics in carbon nanotubes , 2005, cond-mat/0503769.

[8]  White,et al.  Are fullerene tubules metallic? , 1992, Physical review letters.

[9]  B. L. Gyorffy,et al.  Molecular Physics Reports , 1997 .

[10]  Fujita,et al.  Electronic structure of graphene tubules based on C60. , 1992, Physical review. B, Condensed matter.

[11]  A J Pérez-Jiménez,et al.  First-principles phase-coherent transport in metallic nanotubes with realistic contacts. , 2003, Physical review letters.

[12]  Daniel Sánchez-Portal,et al.  Ab initio calculations of the optical properties of 4-Å-diameter single-walled nanotubes , 2002 .

[13]  J. Pople,et al.  Approximate Self‐Consistent Molecular Orbital Theory. II. Calculations with Complete Neglect of Differential Overlap , 1965 .

[14]  R. Hoffmann.  An Extended Hückel Theory. I. Hydrocarbons , 1963 .

[15]  Christian Thomsen,et al.  Carbon Nanotubes: Basic Concepts and Physical Properties , 2004 .

[16]  J. Gimzewski,et al.  Electronics using hybrid-molecular and mono-molecular devices , 2000, Nature.

[17]  Riichiro Saito,et al.  Electronic structure of chiral graphene tubules , 1992 .

[18]  J. Pople,et al.  Approximate Self‐Consistent Molecular Orbital Theory. III. CNDO Results for AB2 and AB3 Systems , 1966 .

[19]  Sawada,et al.  New one-dimensional conductors: Graphitic microtubules. , 1992, Physical review letters.

[20]  Lang,et al.  First-principles calculation of transport properties of a molecular device , 2000, Physical review letters.

[21]  Robert S. Mulliken,et al.  Formulas and Numerical Tables for Overlap Integrals , 1949 .

[22]  A. Rinzler,et al.  Electronic structure of atomically resolved carbon nanotubes , 1998, Nature.

[23]  C. Lieber,et al.  Atomic structure and electronic properties of single-walled carbon nanotubes , 1998, Nature.

[24]  S. Roche,et al.  Electronic transport properties of carbon nanotube based metal/semiconductor/metal intramolecular junctions , 2005, Nanotechnology.

[25]  S. Datta,et al.  A self-consistent transport model for molecular conduction based on extended Hückel theory with full three-dimensional electrostatics. , 2005, The Journal of chemical physics.

[26]  Herbert Shea,et al.  Single- and multi-wall carbon nanotube field-effect transistors , 1998 .

[27]  Supriyo Datta,et al.  Unified description of molecular conduction: From molecules to metallic wires , 2001 .

[28]  The Effects of Finite Length on the Electronic Structure of Carbon Nanotubes , 1998, cond-mat/9808271.

[29]  P L McEuen,et al.  Electrical nanoprobing of semiconducting carbon nanotubes using an atomic force microscope. , 2004, Physical review letters.

[30]  Supriyo Datta,et al.  Electrical Conduction through Molecules , 2003 .

[31]  Yurong Yang,et al.  First-principles study of the (2,2) carbon nanotube , 2005 .