Self-Limiting Growth of Monolayer Tungsten Disulfide Nanoribbons on Tungsten Oxide Nanowires.

Transition metal dichalcogenides (TMDCs) are promising two-dimensional (2D) materials for next-generation optoelectronic devices; they can also provide opportunities for further advances in physics. Structuring 2D TMDC sheets as nanoribbons has tremendous potential for electronic state modification. However, a bottom-up synthesis of long TMDC nanoribbons with high monolayer selectivity on a large scale has not yet been reported yet. In this study, we successfully synthesized long W x O y nanowires and grew monolayer WS 2 nanoribbons on their surface. The supply of source atoms from a vapor-solid bilayer and chemical reaction at the atomic-scale interface promoted a self-limiting growth process. The developed method exhibited a high monolayer selection yield on a large scale and enabled the growth of long (∼100 μm) WS 2 nanoribbons with electronic properties characterized by optical spectroscopy and electrical transport measurements. The produced nanoribbons were isolated from W x O y nanowires by mechanical exfoliation and used as channels for field-effect transistors. The findings of this study can be used in future optoelectronic device applications and advanced physics research.