Investigating the Role of Chirality on the Physical Properties of Boron Nitride and Carbon Nanotubes with Small Diameter

In this research, the electronic structure and optical properties such as dielectric function and optical constants of boron nitride and carbon nanotubes (0,5), (3,3) and (2,4), which all have a small diameter of about 4Å, it has been studied with the help of density functional theory and using first principles. The calculated band structure of these nanotubes shows that carbon nanotubes with a small diameter can have metallic or semiconducting properties depending on the chirality of the nanotube, while boron nitride nanotubes are semiconducting with a high gap regardless of the chirality. In addition, the results of optical calculations indicate that, unlike boron nitride nanotubes, the absorption spectrum of carbon nanotubes with a small diameter strongly depends on the chirality of the nanotube. The results of this research are reported in good agreement with theoretical and experimental data. The emergence of nanotechnology has caused a huge revolution in all aspects of human life, including electronics, medicine, the military, and space industries