Twisted angle effects in the absorption spectra of carbon nanotube

Abstract The spectral characteristics of carbon nanotubes is essential for the development of optoelectronic components and sensors with application in many fields. The linear polarizability absorption spectra of the carbon nanotube with a twisted angle have been calculated by using the tight-binding model and sum-over-state method. First, a structural model of carbon nanotubes based on PPP(Pariser-Parr_Pople) was established, then a certain carbon atom was moved to a position where the carbon nanotubes are angled, and the torsional carbon nanotube structure model was calculated based on the change in bond length. Finally, the absorption spectrum at different twisted angles based on SOS(Sum-over-State) was calculated, and then the detailed analysis was made. It is found that the twisted angle has real impact on the absorption spectra of different types carbon nanotubes. The torsional angle leads to changes in the position and number of absorption peaks of the carbon nanotubes. Its influence on absorption spectra of different types of carbon nanotubes is different, but mainly concentrated in the low frequency region. Exactly, altering the twisted angle has an important effect on the absorption spectra of the carbon nanotube. This work offers a guidance of fabricating carbon nanotubes in the applications of photonic device in many fields.