The effects of nitrogen and boron doping on the optical emission and diameters of single-walled carbon nanotubes

Using TEM, absorption and photoluminescence-excitation spectroscopy we have shown that nitrogen and nitrogen/boron doping of single-walled carbon nanotubes produce significant changes in both the optical properties and the diameter distribution of nanotubes produced by the arc-discharge method. Smaller diameter tubes are preferentially formed in the presence of boron. In addition the presence of nitrogen is found to significantly affect the emission properties of the nanotube ensemble, causing a shift in the dominant emission to lower energies, possibly due to changes in the bundling structure of the nanotubes in solution, but only very small changes are observed in the emission energies for individual nanotubes.