Charge carrier density in Li-intercalated graphene

The electronic structures of bulk C6Li, Li-intercalated free-standing bilayer graphene, and Li-intercalated bilayer and trilayer graphene on SiC(0001) are studied using density functional theory. Our estimate of Young's modulus suggests that Li-intercalation increases the intrinsic stiffness. For decreasing Li-C interaction, the Dirac point shifts to the Fermi level and the associated band splitting vanishes. For Li-intercalated bilayer graphene on SiC(0001) the splitting at the Dirac point is tiny. It is also very small at the two Dirac points of Li-intercalated trilayer graphene on SiC(0001). For all the systems under study, a large enhancement of the charge carrier density is achieved by Li intercalation. (C) 2012 Elsevier B.V. All rights reserved.