Formation of Si-based nanosheets by extraction of Ca from CaSi₂ layers on Si substrates

Abstract

It was demonstrated that flake-like structures containing Si-based nanosheets were successfully synthesized on Si(111) substrates. By exposure of CaSi₂/Si substrates to CrCl₂ vapor, Ca atoms were extracted from CaSi₂, then, the Si-based nanosheets were formed. The structural properties of the Si-based nanosheets formed at the edge of the flakes were examined. It is noted that the flake-like structures were rooted to the substrates, and that the Si-based nanosheets were easily exfoliated from the flake-like structures, to expose the surfaces corresponding to the Si{111} planes of the nanosheet, originated from the corrugated Si(111) layers linked by Ca in CaSi₂.