Graphene-Like Bilayer Hexagonal Silicon Polymorph

Authors

Jaeil Bai, University of Nebraska-LincolnFollow
Hideki Tanaka, Okayama UniversityFollow
Xiao Cheng Zeng, University of Nebraska-LincolnFollow

Date of this Version

2010

Citation

Nano Res. 2010, 3(10): 694–700

Comments

Open Access Article

Abstract

We present molecular dynamics simulation evidence for a freezing transition from liquid silicon to quasi-twodimensional (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.