Abstract
Two-dimensional transition-metal dichalcogenide (TMD) crystals are a versatile platform for optoelectronic, catalytic and quantum device studies. However, the ability to tailor their physical properties through explicit synthetic control of their morphology and dimensionality is a major challenge. Here we demonstrate a gas-phase synthesis method that substantially transforms the structure and dimensionality of TMD crystals without lithography. Synthesis of MoS2 on Si(001) surfaces pre-treated with phosphine yields high-aspect-ratio nanoribbons of uniform width. We systematically control the width of these nanoribbons between 50 and 430 nm by varying the total phosphine dosage during the surface treatment step. Aberration-corrected electron microscopy reveals that the nanoribbons are predominantly 2H phase with zig-zag edges and an edge quality that is comparable to, or better than, that of graphene and TMD nanoribbons prepared through conventional top-down processing. Owing to their restricted dimensionality, the nominally one-dimensional MoS2 nanocrystals exhibit photoluminescence 50 meV higher in energy than that from two-dimensional MoS2 crystals. Moreover, this emission is precisely tunable through synthetic control of crystal width. Directed crystal growth on designer substrates has the potential to enable the preparation of low-dimensional materials with prescribed morphologies and tunable or emergent optoelectronic properties.
Original language | English |
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Pages (from-to) | 29-34 |
Number of pages | 6 |
Journal | Nature Nanotechnology |
Volume | 15 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2020 Jan 1 |
Bibliographical note
Funding Information:We thank B. Frank and H. Fairbrother at Johns Hopkins University (JHU) for assistance with XPS, and also thank the JHU Raman Scattering user centre. T.J.K. acknowledges start-up funding from JHU. J.K. acknowledges postdoctoral funding from the National Research Foundation of Korea (grant no. 2018R1A6A3A03010591). H.-G.P. acknowledges support from the National Research Foundation of Korea (grant no. 2018R1A3A3000666). T.M. acknowledges funding from the National Science Foundation (grant no. DMR-1352373). W.X. and D.H.G. acknowledge funding from the Air Force Office of Scientific Research MURI programme (no. FA9550-16-1-0031). T.H.B. acknowledges funding from the Office of Naval Research through the Naval Research Laboratory Base Program. D.J. and K.J. acknowledge support for this work by the US Army Research Office (contract no. W911NF1910109). T.J.K. and T.M. acknowledge supercomputer resources from the Maryland Advanced Research Computing Center. The near-field microscopy work was carried out at the Singh Center for Nanotechnology at University of Pennsylvania, which is supported by the NSF National Nanotechnology Coordinated Infrastructure Program under grant NNCI-1542153.
Publisher Copyright:
© 2019, The Author(s), under exclusive licence to Springer Nature Limited.
ASJC Scopus subject areas
- Bioengineering
- Atomic and Molecular Physics, and Optics
- Biomedical Engineering
- General Materials Science
- Condensed Matter Physics
- Electrical and Electronic Engineering