Moiré superlattices in strained graphene-gold hybrid nanostructures

Abstract

Graphene-metal nanoparticle hybrid materials potentially display not only the unique properties of metal nanoparticles and those of graphene, but also additional novel properties due to the interaction between graphene and nanoparticles. This study shows that gold nanoislands can be used to tailor the local electronic properties of graphene. Graphene on crystalline gold nanoislands exhibits moiré superlattices, which generate secondary Dirac points in the local density of states. Conversely, the graphene covered gold regions undergo a polycrystalline to Au(111) phase transition upon annealing. Moreover, the nanoscale coexistence of moiré superlattices with different moiré periodicities has also been revealed. Several of these moiré periodicities are anomalously large, which cannot be explained by the standard lattice mismatch between the graphene and the topmost Au(111) layers. Density functional theory and molecular dynamics simulations show for the first time that in such cases the graphene and the interfacial metallic layer is strained, leading to distorted lattice constants, and consequently to reduced misfit. Room temperature charge localization induced by a large wavelength moiré pattern is also observed by scanning tunneling spectroscopy. These findings can open a route towards the strain engineering of graphene/metal interfaces with various moiré superlattices and tailored electronic properties for nanoscale information coding.

25 pages, 6 figures, 1 table

References in corpus (11)

• Energy Gaps in Graphene Nanoribbons
• Emergence of Superlattice Dirac Points in Graphene on Hexagonal Boron Nitride
• Negative Thermal Expansion Coefficient of Graphene Measured by Raman Spectroscopy
• Tailoring the atomic structure of graphene nanoribbons by STM lithography
• Room temperature magnetic order on zigzag edges of narrow graphene nanoribbons
• Anisotropic behaviors of massless Dirac fermions in graphene under periodic potential
• Periodically rippled graphene: growth and spatially resolved electronic structure
• Dirac Cones and Minigaps for Graphene on Ir(111)
• Graphene/Au(111) interaction studied by scanning tunneling microscopy
• Electronic structure, imaging contrast and chemical reactivity of graphene moiré on metals
• Evidence for Superlattice Dirac Points and Space-dependent Fermi Velocity in Corrugated Graphene Monolayer

Cited by in corpus (4)

• Superlattices based on van der Waals 2D materials
• Interaction effects in a chaotic graphene quantum billiard
• Emergence of strain-induced moiré patterns and pseudo-magnetic field confined states in graphene
• Novel graphene/Sn and graphene/SnOx hybrid nanostructures: Induced superconductivity and band gaps revealed by scanning probe measurements