Electronic properties of armchair & zigzag single-walled carbon nanotubes

Abstract

This paper investigates the role of chirality and its impact on the electronic band structure in armchair and zigzag single-walled carbon nanotubes (SWCNTs). Simulating electronic band gaps for single-walled carbon nanotubes (SWCNTs) with various chiral indices has been done by using the tight-binding model.  The increase in chirality results in an increase in the total number of bands in the electronic band structure. A study was conducted on the band gap at Fermi energy (E=0) and it was found that the electronic band structure in armchair and zigzag (SWCNTs) can be either metallic or semiconductor depending on chirality. The diameter of the tube and the band gap value are also provided. The effect of variations in the CNT channel length and oxide thickness on the gate capacitance and drain current of a single CNT have been analyzed.  The results suggest that the simulated values are consistent with the theoretical values thus validating the results.