Unraveling the 3D Atomic Structure of a Suspended Graphene/hBN van der Waals Heterostructure

Author(s)
Giacomo Argentero, Andreas Mittelberger, Mohammad Reza Ahmad Pour Monazam, Yang Cao, Timothy J. Pennycook, Clemens Mangler, Christian Kramberger, Jani Kotakoski, A. K. Geim, Jannik C. Meyer
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. 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.

Organisation(s)
Physics of Nanostructured Materials
Journal
Nano Letters: a journal dedicated to nanoscience and nanotechnology
Volume
17
Pages
1409-1416
No. of pages
8
ISSN
1530-6984
Publication date
03-2017
Publication status
Published
Peer reviewed
Yes
Austrian Fields of Science 2012
103018 Materials physics
Keywords
graphene, hexagonal boron nitride, scanning transmission electron microscopy, van der Waals heterostructures
ASJC Scopus subject areas
Bioengineering, Chemistry(all), Materials Science(all), Condensed Matter Physics, Mechanical Engineering
Electronic versions
https://arxiv.org/abs/1702.02836
Portal url
https://ucris.univie.ac.at/portal/en/publications/unraveling-the-3d-atomic-structure-of-a-suspended-graphenehbn-van-der-waals-heterostructure(72f5b7b6-831e-426f-bb67-6567134334cb).html