Effects of inter-tube coupling on the electro-optical properties of silicon carbide nanotube bundles studied by density functional theory

• We investigated the electronic and optical properties of armchair and zigzag SiC bundles.
• Effects of intertube coupling on the electronic dispersions of SiC bundles are demonstrated.
• Bundling causes broadening, small shifts and increasing of dielectric functions peak positions.
• The calculated dielectric function of (6, 0) SiCNT bundle shows an extra peak at low energies.

The electronic and optical properties of bundled armchair and zigzag silicon carbide nanotubes (SiCNTs) are investigated by using density functional theory. The effects of inter-tube coupling on the electronic dispersions of SiCNT bundles are demonstrated. It was found that the band structure of (6, 0) SiCNT bundle shows metallic feature. The calculated dielectric functions of the armchair and zigzag bundles are similar to that of the isolated tubes, except for the appearance of broadened peaks, small shifts of peak positions about 0.1 eV and increasing of peak intensities. For (6, 0) SiCNT with smaller radius, by considering interband and interaband transitions, the band structure coupling causes an extra peak at low energies.