The Effect of Curvature on the Electronic Structure of Graphene Sheets

It is well-known that a graphene sheet is chemically inert, due to the extensive conjugate π bonding among the carbon atoms on a 2D lattice. Rolling up the graphene sheets produces carbon nanotubes [1], a new class of materials that have attracted much attention in the past few years due to their mechanical and electronic properties. This material can be used, for example, to build molecular sensors, nanoscale devices, or materials with novel properties that may be synthesized using single-walled nanotubes (SWNTs) as the starting point [2, 3]. With a curvature in the graphene sheet, the conjugate π bond should be less effective on the wall of a carbon nanotube than that on a flat graphene sheet, and there is hybridization between the π and σ orbitals. It is interesting to ask whether such changes in bonding would make carbon nanotubes chemically more reactive. As it was said single-walled carbon nanotubes (SWCNs) are produced via rolling up graphene sheet. In this essay we obtain carbon nanotube (8,0) from geraphene sheet through five structures (Figure 1). To investigate these structures, some electronic properties, such as band-structure, density of state (DOS) and charge density are computed.