Formation of single- and double-layer silicon in slit pores

We report on the formation of quasi-two-dimensional nanostructures of silicon by quenching liquid silicon confined in slit nanopores. The formation processes are investigated by molecular-dynamics (MD) calculations using the Tersoff potential. We find that single- or double-layer nanosheets are formed according to the slit width. Both of these nanosheets contain hexagonal planes, and the structure of the single-layer nanosheet is the same as that of graphene. The stability of these nanosheets within the slit nanopore is confirmed by first-principles MD calculations up to 300 K. The present findings demonstrate the possibility of the synthesis of novel nanostructures by confinement in nanopores.