Modeling the doping effect in carbon nanotubes for enhanced conductance

Abstract

In this work we have modelled and simulated the electronic charge transport properties for a Single-walled Carbon Nano-tube with different geometries using first-principle calculations and Non equilibrium Green's function (NEGF) method. We modeled a Single-walled Carbon Nano-tube by rolling Zigzag (4,0) Graphene Nanoribbon strips with the different doping atoms (S,N,P) using semi-empirical Extended Huckle Theory (EHT) within the framework of non-equilibrium green function (NEGF). The simulations were carried in Device mode using Atomistic Tool Kit (ATK-12.8.2) and its graphical interface (custom analyzer) Virtual Nano Lab till the self-consistent results was reached. The effect of the change in conductance and I-V characteristics of the junction was visualized for various transport parameters. The distinct changes in conductance reported as the positions , concentration and type of dopants was varied in central region of the CNT between two electrodes at different bias voltages from -1V to 1 V with steps of .25 V. This suggested conductance enhancement mechanism for the charge transport in the doped Single-walled Carbon Nano-tube at different positions is important for the design of CNT based nano electronic devices.