Revealing the 3D structure of graphene defects

Author(s)
Christoph Hofer, Christian Kramberger, Mohammad Reza Ahmadpour Monazam, Clemens Mangler, Andreas Mittelberger, Giacomo Argentero, Jani Kotakoski, Jannik C. Meyer
Abstract

We demonstrate insights into the three-dimensional (3D) structure of defects in graphene, in particular grain boundaries, obtained via a new approach using two transmission electron microscopy images recorded at different angles. The structure is revealed through an optimization process where both the atomic positions as well as the simulated imaging parameters are iteratively changed until the best possible match to the experimental images is found. We first demonstrate that this method works using an embedded defect in graphene that allows direct comparison to the computationally predicted 3D shape. We then apply the method to a set of grain boundary structures with misorientation angles spanning nearly the whole available range (2.6 degrees-29.8 degrees). The measured height variations at the boundaries reveal a strong correlation with the misorientation angle with lower angles resulting in stronger corrugation and larger kink angles. Our results allow for the first time a direct comparison to theoretical predictions for the corrugation at grain boundaries, revealing the measured kink angles are significantly smaller than the largest predicted ones.

Organisation(s)
Physics of Nanostructured Materials
Journal
2D Materials
Volume
5
No. of pages
8
ISSN
2053-1583
DOI
https://doi.org/10.1088/2053-1583/aaded7
Publication date
10-2018
Peer reviewed
Yes
Austrian Fields of Science 2012
Materials physics, Electron microscopy
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/revealing-the-3d-structure-of-graphene-defects(6c18ef23-9127-45ff-a6f8-fae4bd7aac17).html