Strain induced phase transitions in silicene bilayers: a first principles and tight-binding study

Using first principles and tight-binding calculations, we have investigated the structures of silicene bilayers under the isotropic tensile strain. We find that (i) the strain induce several barrierless phase transitions. (ii) After the phase transitions, the bilayer structures become planar, similar with the AA-stacking graphene bilayers, but combined with the strong covalent interlayer bonds. The tight-binding results demonstrate that this silicene bilayer is characterized by intralayer sp(2) hybridization and the interlayer sp(1) hybridization. (iii) The electronic properties of the silicene bilayers change from semiconducting to metallic with the increase of strain. (C) 2013 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.