Unraveling the 3D atomic structure of a suspended graphene/hBN van der Waals heterostructure

Abstract

In this work we demonstrate that a free-standing van der Waals heterostructure, usually regarded as a flat object, can exhibit an intrinsic buckled atomic structure resulting from the interaction between two layers with a small lattice mismatch. We studied a freely suspended membrane of well aligned graphene on a hexagonal boron nitride (hBN) monolayer by transmission electron microscopy (TEM) and scanning TEM (STEM). We developed a detection method in the STEM that is capable of recording the direction of the scattered electron beam and that is extremely sensitive to the local stacking of atoms. Comparison between experimental data and simulated models shows that the heterostructure effectively bends in the out-of-plane direction, producing an undulated structure having a periodicity that matches the moiré wavelength. We attribute this rippling to the interlayer interaction and also show how this affects the intralayer strain in each layer.

21 pages, 5 figures

References in corpus (5)

• Boron nitride substrates for high-quality graphene electronics
• STM Spectroscopy of ultra-flat graphene on hexagonal boron nitride
• Emergence of Superlattice Dirac Points in Graphene on Hexagonal Boron Nitride
• Cross-sectional imaging of individual layers and buried interfaces of graphene-based heterostructures and superlattices
• Isotope analysis in the transmission electron microscope

Cited by in corpus (13)

• Composite super-moiré lattices in double aligned graphene heterostructures
• Double moiré with a twist: super-moiré in encapsulated graphene
• Elastic constants of graphene: Comparison of empirical potentials and DFT calculations
• Stacking in incommensurate graphene/hexagonal-boron-nitride heterostructures based on ab initio study of interlayer interaction
• Structural, electronic, and optical properties of periodic graphene/h-BN van der Waals heterostructures
• Interferometric 4D-STEM for Lattice Distortion and Interlayer Spacing Measurements in Bilayer and Trilayer Two-dimensional Materials
• $\text{ab initio}$ description of bonding for transmission electron microscopy
• Universal description of potential energy surface of interlayer interaction in two-dimensional materials by first spatial Fourier harmonics
• High-Performance All-Optical Modulator Based on Graphene-hBN Heterostructures
• Strong gate-tunability of flat bands in bilayer graphene due to moiré encapsulation between hBN monolayers
• Hexagonal boron-carbon fullerene heterostructures; Stable two-dimensional semiconductors with remarkable stiffness, low thermal conductivity and flat bands
• Electronic and Spin-Orbit Properties of hBN Encapsulated Bilayer Graphene
• Semimetallic and semiconducting graphene-hBN multilayers with parallel or reverse stacking