Theoretical investigation of substitutionally doped symmetrical finite phenine nanotubes

Abstract

Ab initio density functional theory calculations were performed to investigate the substitutional doping of boron and nitrogen in symmetrical phenine nanotubes. It was found that the doped structures are energetically favorable and can be grown experimentally. Furthermore, we investigated how electronic and magnetic properties of these nanotubes change in the presence of electron-rich (nitrogen) and electron-deficient (boron) impurities, and found that doping in these tubes resulted in a non-magnetic structure. The doping changes the electronic structure of the tube by reducing the energy gap and the reduction value is sensitive to the nanotube diameter and impurity type. The gap corresponding to the nitrogen doped tubes is in the range of 2.38 eV-2.64 eV, whereas for boron doped tubes, the value lies in 1.91 eV to 2.11 eV, respectively. Moreover, the nitrogen doped phenine nanotubes tend to be n-type semi-conductor. The doped phenine nanotube molecules with a high stability and tunable electronic properties may offer several interesting applications in nano-electronics.