Stabilities and mechanical and electronic properties on BN doped zigzag single-wall carbon nanotubes

• Stability of BN doped SWCNT drives by electrostatic interaction between B and N.
• The BN doping causes spin polarization for SWCNT.
• BN doping reduces energy band gap where values depend on substituted position.
• The BN substitution does not alter the Young modulus value of SWCNT.
• Mechanical stress can vary band gap energy of BN doped/undoped SWCNT.

Electronic structures of undoped and BN doped zigzag (8,0) single-walled carbon nanotube (SWCNT) were investigated using density functional theoretical calculations. Their stabilities due to BN doping and spin states were considered and those with the shortest B–N distance and singlet spin is the most stable. The BN substitution also causes the reduction of the band gap energy. While the BN doping reduces the band gap energy from 0.606 to 0.183 eV, it has no effect on the Young׳s modulus value. The band gap energy of SWCNTs can be varied upon applying stress. At high stress ratio, SWCNT could become metallic.