Quasi-Two-Dimensional SiC and SiC₂: Interaction of Silicon and Carbon at Atomic Thin Lattice Plane

Abstract

The band gap of graphene is nearly zero, and thus novel two-dimensional (2D) semiconductor and band gap engineering of graphene is highly desired for advanced optoelectronic applications. Herein, we have experimentally produced quasi-two-dimensional (quasi-2D) SiC by reaction between graphene and a silicon source, which was designed and supported by Born–Oppenheimer molecular dynamics simulations. The lateral length of the as-synthesized quasi-2D SiC is mainly in the range of 0.3–5 μm while the thickness is commonly below 10 nm. Quasi-2D SiC₂ is also found as a byproduct, which is stable over 3 months in air atmosphere. The exciton binding energy of quasi-2D multilayers SiC can reach 0.23 eV while the band gap is around 3.72 eV. Additionally, in situ transmission electron microscopy has firmly proven that quasi-2D SiC can be synthesized through the reaction between graphene and silicon quantum dots. The first production of quasi-2D SiC and SiC₂ makes the band gap engineering in the graphene lattice plane possible