Theoretical Calculation And Analysis Of Electronic Structure Of Single-walled Carbon Nanotube

Nanometarials as one of new materials appear in the 1980s, and the one-dimensional nanomaterials carbon nanotubes are subsequently found, it has a wide application and prospect because it owe a singular physical performance. In principle most basic physical properties of solid can be illustrated and explained by the band theory, while theπelectronic effective quality and its speed play a important role on study carbon nanotubes dynamic application. Thus it is significant to carry out the subject "Theoretical Calculation and Analysis of Electronic Structure of Single-walled Carbon Nanotube".Density functional theory (DFT) is the most important theory method to explore and research the important application prospect functional materials. It is the most accurate energy band calculation method which suday on material electronic state and obtain material characteristic parameters.Here the band structures and density of states (DOS) of three types of chiral single-walled carbon nanotubes (SWNTs) with small diameters (4,1), (4,2) and(5,2)are calculated in the Linux operating system by ABINIT software. In the process of calculation, their curly effect are considered. The calculation result analysis show that (4,1) and (5,2) types of single-walled carbon nanotubes have energy-free forbidden band, they belong to metal type, for (4,1) tube, its owe the largest energy density in -5A2eV; for (5,2) tube, its owe the largest energy density in-6.80eV; While (4,2) type single-walled carbon nanotubes have energy forbidden band, and it's width is 0.24eV, it belongs to semiconductor type, moreover, for (4,2) tube, energy density in place-2.5V is the largest. The conductivity this paper gets and the conclusion of the metal type single-walled carbon nanotube criterion |m-n|=3J(J=0,1,2,3,…) given are consistent.This article calculate the effective quality and the speed ofπelectron in the contracted brillouin zone with high symmetry pointГ, M and A from single-walled carbon nanotube electronic band. Corresponding the three points, their effective qualities are respectively for (?). And the results of the speed areall zero at above three points.It provided a beneficial reference for further researching the single-walled carbon nanotube electronic structure and the mechanical properties.