ABSTRACT
The way the graphene sheet is rolled determines the electronic properties of the tube. In fact, it is possible to have two types of electric behavior of CNTs-metallic or semiconductor-due to the different electronic structures of the tube itself. It is determined by chirality vector Ch and 1D translation vector Τ of the nanotubes. Τ is normal to Ch and together both define the elementary cell of the carbon lattice, or unit cell.
