BxCyNz monolayers with full coverage of fluorine: A study of their structural, electronic and optical properties

Abstract

We have investigated, using first-principles DFT calculations, the structural, electronic, and optical properties of fully fluorinated BxCyNz monolayers. The fluorinated hybrid sheets are derived from BN monolayers with a C nanodomain and from graphene monolayers with a BxNx nanodomain. The former ones display considerably stronger fluorine chemical adsorption. Phonon scattering spectrum shows that even after the deformation of the monolayers, due to the fluorination process, the structures remained mechanically stable. Ab-initio molecular dynamics (AIMD) simulations suggest the stability of fluorinated BxCyNz hybrid monolayers at high temperatures. The band structures of fluorinated hybrid sheets show that they are direct gap semiconductors with similar band gaps. Effective mass of both electron and hole presents isotropic behavior. The graphene monolayers with a BxNx nanodomain show peaks with greater intensity in the visible region, unlike from BN monolayers with a C nanodomain. The size of the nanodomain have influence in the absorption spectrum.