Ab initio density functional theory investigation of Structural and electronic properties of double-wall zinc oxide nanotubes

The electronic properties of double-wall zinc oxide nanotubes (dwznonts) are investigated via density functional theory. the dwznonts are separated into two categories¸ where the inner and outer nanotubes are armchairarmchair and zigzag-zigzag single-wall nanotubes. the band structure of the dwznonts is calculated. our results show that the inter-wall coupling diminishes the energy gap in semiconducting nanotube. we found that the energy gap of dwznonts depends on the structure of the inner and outer walls.