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Improving carrier mobility in two-dimensional semiconductors with rippled materials

Abstract

Two-dimensional (2D) semiconductors could potentially replace silicon in future electronic devices. However, the low carrier mobility in 2D semiconductors at room temperature, caused by strong phonon scattering, remains a critical challenge. Here we show that lattice distortions can reduce electron–phonon scattering in 2D materials and thus improve the charge carrier mobility. We introduce lattice distortions into 2D molybdenum disulfide (MoS2) using bulged substrates, which create ripples in the 2D material leading to a change in the dielectric constant and a suppressed phonon scattering. A two orders of magnitude enhancement in room-temperature mobility is observed in rippled MoS2, reaching 900 cm2 V−1 s−1, which exceeds the predicted phonon-limited mobility of flat MoS2 of 200–410 cm2 V−1 s−1. We show that our approach can be used to create high-performance room-temperature field-effect transistors and thermoelectric devices.

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Fig. 1: Material characterization and phonon DOS in f-MoS2 and r-MoS2.
Fig. 2: Transport mechanism and enhanced dielectric constant and FET performance in r-MoS2.
Fig. 3: Transport measurements of bilayer r-MoS2.
Fig. 4: Thermoelectric properties of mono-, bi- and trilayer r-MoS2 (blue) and f-MoS2 (red) as a function of carrier concentration (n) at 300 K.

Data availability

The data that support the findings of this study are available from the corresponding authors upon reasonable request.

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Acknowledgements

J.W. acknowledges the SERC Central Research Fund (CRF KIMR211001kSERCRF) and Advanced Manufacturing and Engineering Young Individual Research Grant (AME YIRG grant no. A2084c170). D.C. and J.W. acknowledge National Research Foundation Competitive Research Programs (NRFCRP24-2020-0002). M.Y. acknowledges funding support (project IDs 1-BE47, ZE0C, ZE2F and ZE2X) from The Hong Kong Polytechnic University. K.H. acknowledges funding from the Accelerated Materials Development for Manufacturing Program at the Agency for Science, Technology and Research (A*STAR) via the AME Programmatic Fund under grant no. A1898b0043. D.X. and T.L. acknowledge the Young Scientist project of the MOE Innovation platform. D.X. acknowledges the National Natural Science Foundation (NSF) of China (grant no. 62104041) and Shanghai Sailing Program (grant no. 21YF1402600). T.L. acknowledges the NSF of Shanghai (grant no. 22ZR1405700). We acknowledge the Centre for Advanced 2D Materials and Graphene Research at National University of Singapore, and the National Supercomputing Centre Singapore for providing the computing resources.

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Authors

Contributions

J.W. conceived the idea of the experiments and design of the project. J.W. and M.Y. supervised the project. H.-K.N. and D.X. prepared the substrates and fabricated the devices. J.W., H.-K.N., D.X., and T.L. performed the electrical transport characterization. M.Y. and K.Y. conducted the first-principles calculations. Data analysis and interpretations were carried out by J.W., M.Y., H.-K.N., A.S., G.H., K.Y., C.-W.Q., K.H. and G.E., with inputs from the other co-authors. H.-K.N., J.W., A.S., M.Y., G.H. and C.-W.Q. initiated the draft with inputs and comments from all the authors. All the authors discussed the results and provided constructive comments on the manuscript.

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Correspondence to Ming Yang or Jing Wu.

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Nature Electronics thanks Yuanyue Liu, Tibor Grasser and Won Jong Yoo for their contribution to the peer review of this work.

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Supplementary Figs. 1–25, Table 1 and Discussion.

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Ng, H.K., Xiang, D., Suwardi, A. et al. Improving carrier mobility in two-dimensional semiconductors with rippled materials. Nat Electron 5, 489–496 (2022). https://doi.org/10.1038/s41928-022-00777-z

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