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arXiv · 1110.0604

Role of covalent and metallic intercalation on the electronic properties of epitaxial graphene on SiC(0001)

I. Deretzis·A. La Magna
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Abstract

We present an orbital-resolved density functional theory study on the electronic properties of hydrogen and lithium intercalated graphene grown on the Si face of SiC. Starting from the $(6\sqrt3\times6\sqrt3)R30^{\circ}$ surface reconstruction of the graphene/SiC heterosystem, we find that both H and Li can restore the ideal structural characteristics of the two nonequivalent junction parts (i.e. graphene and the SiC substrate) when inserted at the interface. However, the chemical/electrostatic interactions remain different for the two cases. Hence, H-intercalated epitaxial graphene is subject to a sublattice symmetry-breaking electronic interference that perturbs the Dirac point, whereas Li intercalation gives rise to a highly $n$-doped system due to a nonuniform delocalization of Li charges. Results bring to discussion the role of substrate engineering in epitaxial graphene on SiC.

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I. Deretzis, A. La Magna. 2011-11-22. Role of covalent and metallic intercalation on the electronic properties of epitaxial graphene on SiC(0001). https://doi.org/10.1103/physrevb.84.235426

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