Fig. 2: Density functional theory (DFT) calculation of electronic and phonon structure of graphene superlattice.
a Band structure and projected density of states of pristine graphene and graphene superlattice. εF represents the Fermi level. Arrows in (a) correspond to van Hoff singularities. b Charge density difference between the overlapped and exposed carbon atoms in graphene superlattice. c–e Phonon density of states, phonon band structure, and phonon group velocity of graphene superlattice. The overlap ratio of nanopores in graphene superlattice, defined by the ratio of the pore area covered by a neighboring graphene layer to the total pore area, was set to 0.5. The graphene superlattice was Te-doped. The green shaded areas, indicated by arrows in (d), represent the phonon bandgap.
