Nitrogen ion implantation in single wall carbon nanotubes

We report an X-ray photoemission and electron energy loss study on 3 keV N2+ ion implantation in single wall carbon nanotubes. Our results show that nitrogen atoms can bind to carbon in tetrahedral sp3, defects related pyridine-like, and triangular sp2 configurations and such bondings are stable for annealing up to 650 K. Heating at higher temperatures results in preferential substitutional nitrogen doping. This technique opens a new channel for controlled doping in carbon nanotubes for device applications.