Unraveling the 3D Atomic Structure of a Suspended Graphene/hBN van der Waals Heterostructure.
Giacomo ArgenteroAndreas MittelbergerMohammad Reza Ahmadpour MonazamYang CaoTimothy J PennycookClemens ManglerChristian KrambergerJani KotakoskiA K GeimJannik C MeyerPublished in: Nano letters (2017)
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. A 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.
Keyphrases
- electron microscopy
- electronic health record
- carbon nanotubes
- working memory
- room temperature
- high resolution
- big data
- solar cells
- quantum dots
- machine learning
- gold nanoparticles
- mass spectrometry
- loop mediated isothermal amplification
- reduced graphene oxide
- artificial intelligence
- deep learning
- real time pcr
- solid state
- ionic liquid