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Deposition of topological silicene, germanene and stanene on graphene-covered SiC substrates.

ABSTRACT: Growth of X-enes, such as silicene, germanene and stanene, requires passivated substrates to ensure the survival of their exotic properties. Using first-principles methods, we study as-grown graphene on polar SiC surfaces as suitable substrates. Trilayer combinations with coincidence lattices with large hexagonal unit cells allow for strain-free group-IV monolayers. In contrast to the Si-terminated SiC surface, van der Waals-bonded honeycomb X-ene/graphene bilayers on top of the C-terminated SiC substrate are stable. Folded band structures show Dirac cones of the overlayers with small gaps of about 0.1 eV in between. The topological invariants of the peeled-off X-ene/graphene bilayers indicate the presence of topological character and the existence of a quantum spin Hall phase.

SUBMITTER: Matusalem F

PROVIDER: S-EPMC5691050 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature

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Deposition of topological silicene, germanene and stanene on graphene-covered SiC substrates.

Matusalem Filipe F Koda Daniel S DS Bechstedt Friedhelm F Marques Marcelo M Teles Lara K LK

Scientific reports 20171116 1

Growth of X-enes, such as silicene, germanene and stanene, requires passivated substrates to ensure the survival of their exotic properties. Using first-principles methods, we study as-grown graphene on polar SiC surfaces as suitable substrates. Trilayer combinations with coincidence lattices with large hexagonal unit cells allow for strain-free group-IV monolayers. In contrast to the Si-terminated SiC surface, van der Waals-bonded honeycomb X-ene/graphene bilayers on top of the C-terminated SiC ...[more]

PMID: 29146916

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