Activation energy of healing of low-energy irradiation-induced defects in single-wall carbon nanotubes

We analyzed defects created by low-energy irradiation in single-wall carbon nanotubes (SWCNTs) using Raman spectroscopy. The analysis is based on the recovery curves of the G/D ratio and there is no need to assume a specific functional form between the G/D ratio and the defect density. The obtained activation energies of defect healing are 0.7 or 1.4 eV, depending on the extent of the damage, which are close to the values for recombination barriers of vacancy-adatom defects. Calculated recovery curves of the G/D ratio at room temperature show that the recovery is so slow that almost no recovery is observed in a usual time scale, which is consistent with experimental results.