Doping of few-layered graphene and carbon nanotubes using ion implantation

Doping of nanostructured materials using a clean, efficient, and site-selective route such as ion implantation would be hugely desirable for realization of large-scale production methods. Here, ion implantation is used to create uniform impurity-atom densities which are both dose and spatially controlled within multiwalled carbon nanotubes and graphene. The technique is demonstrated for a range of dopants, including silver, representing a likely candidate for optical enhancement, and boron, which is predicted to introduce a plasmon within the visible-frequency regime. Electron energy-loss spectroscopy performed within an aberration-corrected scanning transmission electron microscope, in combination with high-angle-annular-dark-field imaging, is used to pinpoint and identify the bonding configuration of single foreign species within the matrix.