Ultrawide-bandgap Moiré diamanes based on bigraphenes with the twist angles Θ ∼ 30°

Abstract

Moiré diamanes (Dnθ) based on bigraphenes (BGθ) with a layer rotation angle (θ) of about 30° are considered by ab initio methods. The adsorption of hydrogens or fluorines on the bigraphene surface leads to the formation of interlayer covalent bonds. The resulting structure has only sp3-hybridized atoms, which leads to the appearance of a wide bandgap. Bandgaps of hydrogenated Dn29.4 and Dn27.8 and fluorinated F-Dn29.4 and F-Dn27.8 are 3.6, 3.3, 4.1, and 4.5 eV, respectively, which are larger than the dielectric gaps of ordinary diamanes based on the non-twisted AA- or AB-bigraphenes (≈3 eV). Possible applications of these 2D wide-gap dielectrics were also discussed.