First-principles study of Bi and Sb intercalated graphene on SiC(0001) substrate

The atomic structures and electronic properties of antimony and bismuth intercalated graphene on SiC(0001) substrate were investigated using first-principles calculations. The results show that, at Bi and Sb coverages of 1 ML, the Dirac cones were preserved. The π and π* bands of the graphene are barely split by extrinsic spin-orbit interaction from metal layers. At 2/3 ML, the Bi and Sb metal layers form a honeycomb structure, and the Dirac cones remain intact. Furthermore, a notable band splitting at the M point contributed from metal layers was found at 1 ML, whereas a similar splitting at the K point was found at 2/3 ML. Finally, our results show that these two metal intercalations lead to n-type doping of graphene.