▎ 摘　　要

We report on the structural and electronic properties of a single bismuth layer intercalated underneath a graphene layer grown on an Ir(111) single crystal. Scanning tunneling microscopy (STM) reveals a hexagonal surface structure and a dislocation network upon Bi intercalation, which we attribute to a root 3 x root 3 R30 degrees Bi structure on the underlying Ir(111) surface. Ab initio calculations show that this Bi structure is the most energetically favorable and illustrate that STM measurements are most sensitive to C atoms in close proximity to intercalated Bi atoms. Additionally, Bi intercalation induces a band gap (E-g = 0.42 eV) at the Dirac point of graphene and an overall n doping (similar to 0.39 eV) as seen in angular-resolved photoemission spectroscopy. We attribute the emergence of the band gap to the dislocation network which forms favorably along certain parts of the moire structure induced by the graphene/Ir(111) interface.