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Monolayer-to-bilayer transformation of silicenes and their structural analysis.

ABSTRACT: Silicene, a two-dimensional honeycomb network of silicon atoms like graphene, holds great potential as a key material in the next generation of electronics; however, its use in more demanding applications is prevented because of its instability under ambient conditions. Here we report three types of bilayer silicenes that form after treating calcium-intercalated monolayer silicene (CaSi2) with a BF4(-) -based ionic liquid. The bilayer silicenes that are obtained are sandwiched between planar crystals of CaF2 and/or CaSi2, with one of the bilayer silicenes being a new allotrope of silicon, containing four-, five- and six-membered sp(3) silicon rings. The number of unsaturated silicon bonds in the structure is reduced compared with monolayer silicene. Additionally, the bandgap opens to 1.08 eV and is indirect; this is in contrast to monolayer silicene which is a zero-gap semiconductor.

SUBMITTER: Yaokawa R

PROVIDER: S-EPMC4748253 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature

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Monolayer-to-bilayer transformation of silicenes and their structural analysis.

Yaokawa Ritsuko R Ohsuna Tetsu T Morishita Tetsuya T Hayasaka Yuichiro Y Spencer Michelle J S MJ Nakano Hideyuki H

Nature communications 20160205

Silicene, a two-dimensional honeycomb network of silicon atoms like graphene, holds great potential as a key material in the next generation of electronics; however, its use in more demanding applications is prevented because of its instability under ambient conditions. Here we report three types of bilayer silicenes that form after treating calcium-intercalated monolayer silicene (CaSi2) with a BF4(-) -based ionic liquid. The bilayer silicenes that are obtained are sandwiched between planar cry ...[more]

PMID: 26847858

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