Graphene-like bilayer hexagonal silicon polymorph
Bilayer hexagonal silicon, slit pore, semimetal, two-dimensional 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.
Tsinghua University Press
Jaeil Bai,Hideki Tanaka,Xiao Cheng Zeng, Graphene-like bilayer hexagonal silicon polymorph. NanoRes.2010, 3(10): 694–700