Epitaxial growth has become a promising route to achieve highly crystalline continuous two-dimensional layers. However, high-quality layer production with expected electrical properties is still challenging due to the defects induced by the coalescence between imperfectly aligned domains. In order to control their intrinsic properties at the device scale, the synthesized materials should be described as a patchwork of coalesced domains. Here, we report multi-scale and multistructural analysis on highly oriented epitaxial WS2 and WSe2 monolayers using scanning transmission electron microscopy (STEM) techniques. Characteristic domain junctions are first identified and classified based on the detailed atomic structure analysis using aberration corrected STEM imaging. Mapping orientation, polar direction and phase at the micrometer scale using four-dimensional STEM enabled to access the density and the distribution of the specific domain junctions. Our results validate a readily applicable process for the study of highly oriented epitaxial transition metal dichalcogenides, providing an overview of synthesized materials from large scale down to atomic scale with multiple structural information.
@article{arxiv.2306.05505,
title = {Mapping domain junctions using 4D-STEM: toward controlled properties of epitaxially grown transition metal dichalcogenide monolayers},
author = {Djordje Dosenovic and Samuel Dechamps and Celine Vergnaud and Sergej Pasko and Simonas Krotkus and Michael Heuken and Luigi Genovese and Jean-Luc Rouviere and Martien den Hertog and Lucie Le Van-Jodin and Matthieu Jamet and Alain Marty and Hanako Okuno},
journal= {arXiv preprint arXiv:2306.05505},
year = {2023}
}