Nitrogen and boron doping effects on the electrical conductivity of graphene and nanotube

The effects of nitrogen and boron doping on the density of states and the temperature dependence of the electrical conductivity of graphene plane and (10,0) single-walled carbon nanotube are studied. We apply the Green's function technique and coherent potential approximation within the tight-binding Hamiltonian model. We find that when dopants are introduced, van-Hove singularities in the density of states are broadened and Fermi level is shifted. The shift of the Fermi-energy depends on concentration of nitrogen and boron atoms doping. The electrical conductivity changes with the dopant concentration in the two temperature regions. In the low temperature region, the electrical conductivity increases when dopant concentration increases while the electrical conductivity decreases with increasing concentration of nitrogen and boron atoms in the high temperature region. (C) 2011 Elsevier Masson SAS. All rights reserved.