▎ 摘　　要

We report the structure, electronic band structures, and total and partial electron density of states of strontium intercalation in the AA bilayer of graphene (Sr-intercalated AA stacked BG) from first-principles calculations. Our results show that the Sr intercalation influences the electronic properties. Indeed, we observed the contribution of the Sr atom to the band gap formation. The p and d orbitals of the Sr atom have a remarkable contribution to the formation of the DOS of the Sr-intercalated AA stacked BG. The Dirac point where the gap is non-zero in the AA stacked BG is located at about 1.38 eV below the Fermi level. Thus, the electron density is maximal around the C atoms, which leads to an efficient transfer of electric charges from the Sr atom to the C atoms. In addition, we have exploited the complex dielectric function to calculate the absorption coefficient, refractive index, and extinction index. The static refractive index increases in vertical polarization and diverges in parallel mode, confirming the pure metallic behavior of the Sr-intercalated AA stacked BG material. Moreover, the value of the absorption coefficient in the visible region increases in the vertical mode while it decreases in the parallel direction. These results indicate that AA stacked BG intercalated by Sr has relevant properties for optoelectronic and ultrafast devices.