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

Moire diamanes (Dn theta) based on bigraphenes (BG theta) with a layer rotation angle (theta) of about 30 degrees 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 sp(3)-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 4.5eV, respectively, which are larger than the dielectric gaps of ordinary diamanes based on the non-twisted AA- or AB-bigraphenes (approximate to 3eV). Possible applications of these 2D wide-gap dielectrics were also discussed.