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Healing of donor defect states in monolayer molybdenum disulfide using oxygen-incorporated chemical vapour deposition

Nature Electronics volume 5, pages 28–36 (2022)Cite this article

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Abstract

Two-dimensional molybdenum disulfide (MoS2) is a semiconductor that could be used to build scaled transistors and other advanced electronic and optoelectronic devices. However, the material typically exhibits strong n-type doping, low photoluminescence quantum yields and high contact resistance with metals, behaviour that is often attributed to the presence of donor states induced by sulfur vacancies. Here we show that oxygen-incorporated chemical vapour deposition can be used to passivate sulfur vacancies and suppress the formation of donor states in monolayer MoS2. First-principles calculations and spectroscopy measurements are used to reveal the formation of molybdenum–oxygen bonding at the sulfur vacancy sites and the absence of donor states in oxygen-incorporated MoS2. Compared with MoS2 fabricated via chemical vapour deposition without oxygen, oxygen-incorporated MoS2 exhibits enhanced photoluminescence, higher work function and improved contact resistance with a lower Schottky barrier (less than 40 meV) at the metal/MoS2 interface.

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Fig. 1: Deposition of monolayer MoS2 with and without oxygen incorporation.
Fig. 2: Reduction in electron doping of monolayer O-MoS2.
Fig. 3: Atomic structures and DFT calculation results of the effect of oxygen healing.
Fig. 4: Electrical characterization of monolayer O-MoS2 FETs.
Fig. 5: Gate-dependent PL at 78 K.

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The data that support the findings within this paper are available from the corresponding author upon reasonable request.

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Acknowledgements

P.-C.S., H.W. and J.K. acknowledge financial support from the Center for Energy Efficient Electronics Science (NSF award no. 0939514). P.-C.S., Y.L., A.-Y.L., J.-H.P., T.P. and J.K. acknowledge the US Army Research Office (ARO) through the Institute for Soldier Nanotechnologies at MIT, under cooperative agreement no. W911NF-18-2-0048. C.M. and K.E.A. acknowledge support of grant NSF-DMR 1708970. C.S., J.-H.P., X.J., T.P. and J.K. acknowledge support from the US ARO MURI project under grant no. W911NF-18-1-0432. J.L. acknowledges support by the Office of Naval Research MURI through grant no. N00014-17-1-2661. Y.G., Y.L., N.M. and J.K. acknowledge support by the US Department of Energy, Office of Science, Basic Energy Sciences, under award DE-SC0020042. X.W. and X.L. acknowledge support of the Semiconductor Research Corporation. This work was supported in part by the STC Center for Integrated Quantum Materials, NSF grant no. DMR-1231319. This work was performed in part at the Center for Nanoscale Systems (CNS)—a member of the National Nanotechnology Coordinated Infrastructure Network, which is supported by the National Science Foundation under NSF award no. 1541959. CNS is part of Harvard University.

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Author notes

  1. These authors contributed equally: Pin-Chun Shen, Yuxuan Lin.

Authors and Affiliations

  1. Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA

    Pin-Chun Shen, Yuxuan Lin, Ang-Yu Lu, Xiang Ji, Haozhe Wang, Nannan Mao, Yunfan Guo, Ji-Hoon Park, Tomás Palacios & Jing Kong

  2. Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA

    Cong Su & Ju Li

  3. Department of Physics, Mount Holyoke College, South Hadley, MA, USA

    Christina McGahan & Katherine E. Aidala

  4. Department of Chemistry, Boston University, Boston, MA, USA

    Xingzhi Wang & Xi Ling

  5. Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA

    Nannan Mao & William Tisdale

  6. Institute of Microelectronics, Tsinghua University, Beijing, China

    Yan Wang

  7. Division of Materials Science and Engineering, Boston University, Boston, MA, USA

    Xi Ling

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Contributions

P.-C.S., Y.L. and J.K. conceived and designed the experiments. P.-C.S. performed the MoS2 growth and characterization supervised by J.K. P.-C.S. and Y.L. carried out the device fabrication and characterization supervised by T.P. Y.L., P.-C.S. and X.W. performed the low-temperature optical measurements supervised by X.L. C.M. carried out the EFM measurements and interpreted the data supervised by K.E.A. A.-Y.L. performed the doping and strain characterization and analysed the Raman and XPS data. C.S. performed the TEM measurement supervised by J.L. C.S. and X.J. conducted the DFT calculations supervised by J.L. and Y.W. H.W. performed the XPS measurement. N.M. conducted the second-harmonic generation study supervised by W.T. Y.G. and X.J. assisted with further O-MoS2 synthesis. P.-C.S., Y.L. and J.K. co-wrote the paper. All the authors regularly discussed the results and commented on the manuscript.

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Correspondence to Jing Kong.

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Shen, PC., Lin, Y., Su, C. et al. Healing of donor defect states in monolayer molybdenum disulfide using oxygen-incorporated chemical vapour deposition. Nat Electron 5, 28–36 (2022). https://doi.org/10.1038/s41928-021-00685-8

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