Electronic properties and stability of three new kinds of single-atom-thick SIC graphyne sheets

TL;DR

This study introduces three novel single-atom-thick silicon-carbon graphyne sheets with unique electronic properties and confirmed stability, expanding the potential for advanced 2D materials in electronics.

Contribution

The paper reports the discovery and characterization of three new stable Si-C graphyne structures, including the novel 'bone position' concept and their electronic and structural properties.

Findings

SiC and Si1C9 have band gaps of 0.955 eV and 0.689 eV.

Si2C8 exhibits a buckled structure with a Dirac cone.

All three structures are thermally stable.

Abstract

Three new single-atom-thick silicon-carbon stable systems have been found by using of SCED-LCAO and DFT methods. An important position, named bone position, is proposed in these structures. For SiC and Si1C9 system, the bone positions are partially occupied by Si atoms, the plane structure is kept and electronic gap is opened with 0.955 eV and 0.689 eV respectively. For Si2C8 system, the bone positions are fully occupied by Si atoms. It shows a buckled structure with a buckling of 0.05 {\AA} and a Dirac cone at M point. Moreover, the sp hybridization between Si and C atoms in SiC system is found and the co-existence of sp, sp2 and sp3 hybridization is also found in Si2C8 system. The thermal stability for these three systems is certified.