Soft Synthesis of Single‐Crystal Silicon Monolayer Sheets

Abstract

Transparent Si nanosheets with a thickness of 0.37 nm are produced by chemically exfoliating calcium disilicide with propylamine hydrochloride (PA⋅HCl; see picture, Ca white, Si red). The nanosheets have a two‐dimensional silicon backbone and are an order of magnitude thinner than previously reported silicon nanostructures.

Synthesis and modification of two-dimensional crystalline silicon nanosheets

“…To achieve this, Mg-doped CaSi 2 was used as a starting material to decrease the strength of the interactions between the Ca 2+ and (Si ¹ ) n layers. 36) The immersion of bulk CaSi 1.85 Mg 0.15 in a solution of propylamine hydrochloride led to the deintercalation of the calcium ions, which was accompanied by the evolution of hydrogen. The CaSi 1.85 Mg 0.15 was then converted into a mixture of SiNSs and an insoluble black metallic solid.…”

Direct Observation of Dirac Cone in Multilayer Silicene Intercalation Compound CaSi2

“…It is noted here that several challenges, such as controlling the Ca content in Ca x Si 2 and chemically exfoliating silicene layers from CaSi 2 , have been in progress. [ 21 ] In summary, we reported the results of ARPES study on tr3-CaSi 2 which is regarded as Ca-intercalated multilayer silicene. In the ARPES-derived band structure, we observed the massless Dirac-cone π-electron dispersions at the K(H) point in the Brillouin zone, together with the σ-band dispersions at the Γ point.…”

“…[ 21 ] Mixture of 99.999 wt% Si and 99.99 wt% Ca with the Ca-excess off-stoichiometric composition Ca 1.1 Si 2 was used as a starting material, since Ca is likely to evaporate from the CaSi 2 melt due to the high vapor pressure. This starting material was melted in a Ta crucible by high-frequency induction heating under an argon atmosphere, and cooled down to the room temperature to obtain a polycrystalline CaSi 2 ingot.…”

Electrical Transport Model of Silicene as a Channel of Field Effect Transistor

“…One atomic thick crystalline form of the silicon atoms with sp 3 bond arranged in a honeycomb lattice structure so called Silicene ( fig. 1a), has been experimentally observed by Nakano, et al for the first time [11]. First principles calculation based on density functional theory (DFT) showed that despite carbon atoms that make two demensional planar sheet, Silicene makes stable bounds in the semi two dementional (semi-2D) hexagon form [12].…”