The stability and electronic properties of a new allotrope of silicene and silicon nanotube

The new allotropes of silicene and silicon nanotubes (SiNTs) are explored by density functional theory (DFT). They are made up of alternating four-membered ring and eight-membered ring. The results show that this new SiNTs are sp(3) or sp(2)-sp(3) hybridization based on the different types of structures. The possible existence of the planar silicene is also discussed. Besides, the average binding energies and thermal properties show that the silicene and SiNTs have high stabilities. Finally, the electronic properties are obtained, it reveals that all of these new SiNTs (armchair or zigzag) studied in this paper have a narrow band gap. (C) 2016 Elsevier Ltd. All rights reserved.