Investigation the Optical Properties and thermal conductivity of N-doped Carbon Nanotubes in the presence of Electric field

The optical properties and thermal conductivity of carbon nanotubes in the presence of Nitrogen doping and electric field investigated via the Green's function method and tight binding approximation. The doping and external fields lead to modifications in the density of state (DOS), optical properties, electrical and thermal conductivity. The band gap decreases by the electric field until reaches zero and nanotubes with larger radius are more sensitive than small ones. The number and energies of peaks in the in the DOS and optical spectra are dependent on the electric field strength and doping concentration. The electrical and thermal conductivity increases with temperature until reaches maximum value then decreases. The behaviors of these parameters in the external electric field are different for pure and doped systems. By increasing the doping concentration and electric field strength, they decreases in higher temperature.