The structural and electronic properties of chiral SiC nanotubes: a hybrid density functional study

Hybrid density functional theory was employed in investigating the structural and electronic properties of 14 chiral and 3 armchair SiC nanotubes (SiCNTs). The role of the tube diameter, as well as that of the chiral angle v, was studied in detail by considering nanotubes of diameters varying from 2 to 9 angstrom and chiral angles v varying between 7 degrees and 30 degrees. The study revealed that all the investigated SiCNTs are semiconductors with a broad spectrum of bandgap values ranging from 0.2 to 2.9 eV and that the structural stability of the nanotubes increases with diameter. By analyzing the behavior of the molecular orbitals, an explanation of the mechanism by which v affects the determination of such values is put forward.