Ab initiostudy of OH-functionalized single-wall carbon nanotubes

The effects of the OH group on the electronic and optical properties of single-wall carbon nanotubes were investigated using first principles electronic structure calculations. Our results confirm band-gap reduction of semiconductor carbon nanotubes up on addition of the OH group. An additional energy level emerges near the Fermi level, which is due to coupling between one $p$ orbital of the oxygen with the big $\mathrm{\pi }$ bond of the nanotube. Analysis of loss function showed that the plasmon excitation shifts to lower frequency.