, Volume 3, Issue 10, pp 694-700,
Open Access This content is freely available online to anyone, anywhere at any time.
Date: 21 Sep 2010

Graphene-like bilayer hexagonal silicon polymorph


We present molecular dynamics simulation evidence for a freezing transition from liquid silicon to quasi-two-dimensional (quasi-2D) bilayer silicon in a slit nanopore. This new quasi-2D polymorph of silicon exhibits a bilayer hexagonal structure in which the covalent coordination number of every silicon atom is four. Quantum molecular dynamics simulations show that the stand-alone bilayer silicon (without the confinement) is still stable at 400 K. Electronic band-structure calculations suggest that the bilayer hexagonal silicon is a quasi-2D semimetal, similar to a graphene monolayer, but with an indirect zero band gap. http://static-content.springer.com/image/art%3A10.1007%2Fs12274-010-0032-6/MediaObjects/12274_2010_32_Fig1_HTML.jpg