Structural, electronic and optical properties of AB bilayer graphene intercalated by Sr atom: A first principles study

The current study investigates the intercalation of the alkaline metal Sr atom in the AB stacked bilayer graphene system and their effect on the structural, electronic and optical properties using density functional theory (DFT) calculations. The results indicate that the intercalated structure crystallizes in the hexagonal system with the SrC6 structure type, and it is energetically more stable than the pure structure. The electronic behavior of AB stacked bilayer graphene is semi-metallic. In contrast, the behavior of the Sr-intercalated AB stacked bilayer graphene changes to metallic with a Dirac point is located about 1.33 eV under the Fermi level. Optical properties have been calculated under electric fields polarized both parallel and perpendicular to the z-axis. The calculated optical properties show the anisotropic behavior for the dielectric function, absorption coefficient, refractive and extinction coefficients. After the intercalation of the Sr atom, the static refractive index increase in the perpendicular polarization. In addition, the photoluminescence phenomenon was assured for the pure and intercalated bilayer graphene. The research results provide a basis for developing graphene intercalation compounds in optoelectronic nanodevices. [Display omitted] •The results indicate that the intercalated structure Sr/AB − BG is energetically more stable than the pure AB – BG.•The electronic behavior of AB − BG is semi-metallic, while the behavior Sr/AB − BG changes to metallic.•The calculated optical properties show an anisotropic behavior.•After the intercalation of Sr atom the static refractive index increases in the perpendicular polarization.•The photoluminescence phenomenon was assured for the pure and intercalated bilayer graphene.