Ab initio density functional theory investigation of crystalline bundles of polygonizedsingle-walled silicon carbide nanotubes

Abstract

By using ab initio density functional theory, the structural characterizations and electronicproperties of two large-diameter (13, 13) and (14, 14) armchair silicon carbidenanotube (SiCNT) bundles are investigated. Full structural optimizations show thatthe cross sections of these large-diameter SiCNTs in the bundles have a nearlyhexagonal shape. The effects of inter-tube coupling on the electronic dispersions oflarge-diameter SiCNT bundles are demonstrated. By comparing the band structures of thetriangular lattices of (14, 14) SiCNTs with nearly hexagonal and circular crosssections we found that the polygonization of the tubes in the bundle leads to afurther dispersion of the occupied bands and an increase in the bandgap by 0.18 eV.