▎ 摘 要
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 pi and pi* 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. (C) 2013 Elsevier B.V. All rights reserved.