High-Mobility and High-Optical Quality Atomically Thin WS2
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The rise of atomically thin materials has the potential to enable a paradigm shift in modern technologies by introducing multi-functional materials in the semiconductor industry. To date the growth of high quality atomically thin semiconductors (e.g. WS2) is one of the most pressing challenges to unleash the potential of these materials and the growth of mono- or bi-layers with high crystal quality is yet to see its full realization. Here, we show that the novel use of molecular precursors in the controlled synthesis of mono- and bi-layer WS2 leads to superior material quality compared to the widely used topotactic transformation of WO3-based precursors. Record high room temperature charge carrier mobility up to 52 cm2/Vs and ultra-sharp photoluminescence linewidth of just 36 meV over submillimeter areas demonstrate that the quality of this material supersedes also that of naturally occurring materials. By exploiting surface diffusion kinetics of W and S species adsorbed onto a substrate, a deterministic layer thickness control has also been achieved promoting the design of scalable synthesis routes.
C.M. would like to acknowledge the EPSRC awards EP/K033840/1, EP/K01658X/1, EP/K016792/1, EP/M022250/1, the EPSRC-Royal Society Fellowship Engagement Grant EP/L003481/1 and the award of a Royal Society University Research Fellowship by the UK Royal Society. N.N. acknowledge the Imperial College Junior Research Fellowship and P.C.S. would like to acknowledge the funding and support from the European Commission (H2020 – Marie Sklodowska Curie European Fellowship–660721). I.A. acknowledges financial support from The European Commission Marie Curie Individual Fellowships (Grant number 701704). J.D.M. acknowledges the financial support from the Engineering and Physical Sciences Research Council (EPSRC) of the United Kingdom, via the EPSRC Centre for Doctoral Training in Metamaterials (Grant No. EP/L015331/1). S.R. and M.F.C acknowledge financial support from EPSRC (Grant no. EP/J000396/1, EP/K017160/1, P/K010050/1, EP/G036101/1, EP/M001024/1, EP/M002438/1), from Royal Society international Exchanges scheme 2016/R1 and from The Leverhulme trust (grant title “Quantum Drums” and “Room temperature quantum electronics”).
This is the final version of the article. Available from Springer Nature via the DOI in this record.
Vol. 7, article 14911