The interwall effects in the electronic structure of commensurate triple-walled carbon nanotubes

Carbon nanotubes, since their discovery, have become an important material in the field of nanotechnology due to their unique one-dimensional nanostructure and exceptional electronic, mechanical, and thermal properties. This study uses a tight-binding model to analyze the electronic structure of commensurate triple-walled carbon nanotubes (TWCNTs), focusing on the role of interwall coupling. In the decoupled case, the energy bandgaps are determined by the layers with the narrower bandgaps. In the coupled case, the energy bandgap of semiconducting–semiconducting tubes decreases with increasing interwall coupling tp1 and tp2 within the range 0 ≤ tp1 ≤ 0.35 eV, 0 ≤ tp2 ≤ 0.35 eV. In addition, the bandgap is found to approximately follow an inverse scaling with the chiral index d (Eg ∝ 1/d). These findings enhance the understanding of the electronic properties of TWCNTs and their dependence on interwall interactions.