The effects of boron doping on the optical absorption of carbon nanotubes

The frequency behavior of optical conductivity of (9,0) zigzag carbon nanotube doped with Boron atoms, as acceptor impurities, has been addressed. In the context of tight binding model Hamiltonian. In order to study of doping effects, we add a local energy term to original Hamiltonian of the clean system. This term presents the effect of scattering of electrons from impurities through carbon nanotube. Green's function of the disordered system is found using self-consistent Born approximation. Linear response is employed to calculate the optical conductivity of disordered carbon nanotube in terms of electronic Green's function. The effects of both dopant concentration and tube's diameter are investigated in details. The results show the optical conductivity is independent of boron concentrations in high frequency region. At low frequencies values, the increase of boron concentration leads to reduce optical absorption spectra. Moreover, optical conductivity gets the higher amounts at high frequency when the temperature raises.