Effect of boron and nitrogen co-doping on CNT's electrical properties: Density functional theory

In this work, we have theoretically studied the changes in electrical properties of three different geometrical structures of carbon nanotubes upon co-doping them with boron and nitrogen atoms. We applied different doping mechanisms to study band structure variations in the doped structures. Doping carbon nanotubes with different atoms will create new band levels in the band structure and as a consequence, a shift in the Fermi level occurs. Whereas, filling up the lowest conduction/ upper valence bands created an up/ downshift in the Fermi level. Moreover, dopants concentration and dopants position play a critical rule in defining the number of new band levels. These new band levels in the band gap region represented as new peaks appeared in the density of states. These new bands are solely attributed to co-doping carbon nanotubes with boron and nitrogen atoms.