Conductivity Modulation of SWCNT by Its Sidewall Functionalization Through Heavily Doping with DNA Nucleobase Adenine

摘要

Electronic property of the single-walled carbon nanotube can be tailored by heavily doping with DNA nucleobase adenine. Pristine metallic zigzag form of single-walled carbon nanotube (6, 0) is functionalized with one and four adenine molecules using Atomistix ToolKit Virtual NanoLabQuantumWise simulation software. Metallic single-walled nanotube retains its metallic property with single adenine molecule doping. Suppression of the metallic property and conversion of metallic nanotube to semiconductor is achieved upon heavily doping with adenine. Comparative analysis ofthe band structures, zero bias transmission spectra, density of states and I – V curve of the pristine nanotube and the coupled systems support this result. This conversion is brought about by sp ~(2) to sp ~(3) re-hybridization in the nanotubestructure by its functionalization. In the zigzag, metallic nanotube, actual π – π ~(*) band crossing the Fermi level is disrupted by heavily doping and a bandgap emerges near the Fermi level explaining that the metallic nanotube is converted to a semiconductingone. The bandgap value of the surface-engineered single-walled carbon nanotube with four adenine molecules is found to be 0.023387 eV.