Stability and electronic structures of double-walled armchair germanium carbide nanotubes

摘要

First-principle calculations based on density functional theory have been used to investigate the stability and electronic structures of double-walled (n(1), n(1))@(n(2), n(2)) (4 <= n(1) <= 8, n(1) + 3 <= n(2) <= n(1) + 6) germanium carbide nanotubes (GeCNTs). For any given (n(1), n(1)) inner tube, the corresponding (n(1), n(1))@(n(1) + 5, n(1) + 5) GeCNT has the highest formation energy and binding energy per atom, which indicate that the (n(1), n(1))@(n(1) + 5, n(1) + 5) nanotube is stable. The (5,5)@(10,10) GeCNT has been found to be a particularly stable geometry. The interlayer interaction between the two layers of the double-walled GeCNT leads to an obvious coupling, which results in a narrowing of the band gap. (C) 2015 Elsevier B.V. All rights reserved.