Interfacial Reconstructed Layer Controls the Orientation of Monolayer Transition-Metal Dichalcogenides

Abstract

<p>Growingcontinuous monolayer films of transition-metaldichalcogenides(TMDs) without the disruption of grain boundaries is essential torealize the full potential of these materials for future electronicsand optoelectronics, but it remains a formidable challenge. It isgenerally believed that controlling the TMDs orientations on epitaxialsubstrates stems from matching the atomic registry, symmetry, andpenetrable van der Waals forces. Interfacial reconstruction withinthe exceedingly narrow substrate-epilayer gap has been anticipated.However, its role in the growth mechanism has not been intensivelyinvestigated. Here, we report the experimental conformation of aninterfacial reconstructed (IR) layer within the substrate-epilayergap. Such an IR layer profoundly impacts the orientations of nucleatingTMDs domains and, thus, affects the materials' properties.These findings provide deeper insights into the buried interface thatcould have profound implications for the development of TMD-basedelectronics and optoelectronics.</p>