Binary transition metal dichalcogenide monolayers share common properties such as a direct optical bandgap, spin-orbit splittings of hundreds of meV, light–matter interaction dominated by robust excitons and coupled spin-valley states. Here we demonstrate spin-orbit-engineering in Mo[(1-x)]WxSe2 alloy monolayers for optoelectronics and applications based on spin- and valley-control. We probe the impact of the tuning of the conduction band spin-orbit spin-splitting on the bright versus dark exciton population. For MoSe2 monolayers, the photoluminescence intensity decreases as a function of temperature by an order of magnitude (4–300 K), whereas for WSe2 we measure surprisingly an order of magnitude increase. The ternary material shows a trend between these two extreme behaviors. We also show a non-linear increase of the valley polarization as a function of tungsten concentration, where 40% tungsten incorporation is sufficient to achieve valley polarization as high as in binary WSe2.
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- Spin-Orbit Engineering in Transition Metal Dichalcogenide Alloy Monolayers
- Wang, Gang (Author)
- Robert, Cedric (Author)
- Tuna, Aslihan (Author)
- Chen, Bin (Author)
- Yang, Sijie (Author)
- Alamdari, Sarah (Author)
- Gerber, Iann C. (Author)
- Amand, Thierry (Author)
- Marie, Xavier (Author)
- Tongay, Sefaattin (Author)
- Urbaszek, Bernhard (Author)
- Ira A. Fulton Schools of Engineering (Contributor)
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Digital object identifier: 10.1038/ncomms10110
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Identifier TypeInternational standard serial numberIdentifier Value2041-1723
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The final version of this article, as published in Nature Communications, can be viewed online at: https://www.nature.com/articles/ncomms10110
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Wang, G., Robert, C., Suslu, A., Chen, B., Yang, S., Alamdari, S., . . . Urbaszek, B. (2015). Spin-orbit engineering in transition metal dichalcogenide alloy monolayers. Nature Communications, 6, 10110. doi:10.1038/ncomms10110