Modeling transport properties of single-wall carbon nanotube between metal and graphene electrodes

Abstract

In this article, transport properties of a single-wall carbon nanotube having chirality (4, 0), connected to copper, gold and graphene electrodes, have been investigated. Electronic structures have been analyzed using the density functional theory calculator. Transport properties of the devices formed by interfacing of single-wall carbon nanotube and electrodes are computed using the nonequilibrium Green’s functional method coupled with density functional theory approach. Contact effects due to metal–carbon nanotube interface have significant impact on transport properties of charge carriers. Therefore, transport properties have been critically analyzed with the help of transmission spectra, differential conductance and conductance plots and I–V characteristics. From these results, it has been concluded that formulation of the electrode material is not the single-factor responsible for creating conduction problems. Along with the electrode material, interface position of metal–carbon nanotube configuration and heterostructure contacts are also responsible in influencing transport phenomenon. In this way, varying the contact geometry is found to play an important role in integrated circuit interconnect technologies for exploring the transport properties. Gold is best among all three simulated contact electrodes, and for low-power applications, graphene can be next choice over an applied bias range of −1 to +1 V. Atomistix software tool has been used to analyze transport properties of interconnect models.