Nitrogen doping of single walled carbon nanotubes by low energy N2+ ion implantation

Nitrogen doping in single walled carbon nanotubes by 300 eV N2+ ion implantation has been studied with X-ray photoelectron spectroscopy. We investigated the nitrogen doping concentration in the range of 1.5–11.3 at.% and post-irradiation annealing up to 1000 °C. We found that nitrogen atoms can be substitutionally inserted into the perfect sp2 hexagonal network, or bind to two sp2 carbon neighbors in a pyridine-like configuration, or be connected to three or four sp3 carbon atoms in a reconstructed double vacancy site and that the substitutional doping is the most stable bonding against high temperature annealing.