Optoelectronic properties of silicon nanotubes with electron-electron interactions in orthogonal tight-binding model

We investigate the electron-electron (e-e) interactions effect on the optoelectronic properties of zigzag silicon hexagonal nanotubes (Si h-NTs). Analytic expressions for the band structure and optical absorption of Si h-NTs have been derived based on orthogonal tight-binding (OTB) method. We combine OTB method and Hubbard model and show electron-electron interactions effect on the band structure of metallic and semiconducting zigzag nanotubes for the first and second-nearest neighbor. Moreover, the optical matrix elements and optical absorption are analytically derived for light polarization parallel to the tube axis in low energy for first nearest-neighbor (1NN) and second nearest-neighbor (2NN) approximation. It is found that the electron-electron interactions do not modify the optical absorption spectrum of zigzag Si h-NTs. These results can be beneficial for the explanation of resonant Raman Spectra of nanotube samples.