Modeling of sub-band and diameter effect in carrier concentration of CNTFET

Also in this paper the band structure of the rolled-up nanotube can be obtained by zone-folding from the band structure of the graphene sheet. This method is used in this work and we simulated and analyzed the band structure of carbon nanotube. We present analytical modeling of carrier concentration in a zigzag semiconducting of carbon nanotube field effect transistor (CNFET) using the dispersion relation E(k) (the first three sub-bands) and given the density of states (DOS), the carrier concentration is obtained based on a numerical method as an alternative to the usual Fermi-Dirac integrals. In order to find the influence of the first three sub-bands energy and diameter dt of CNT in non-degenerate and degenerate region of the carrier concentration in CNTFET. The results obtained showed that the diameter and the energy of sub-band have a significant impact on the carrier concentration of CNTFET.