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High carrier mobility in graphene doped using a monolayer of tungsten oxyselenide

An Author Correction to this article was published on 24 November 2021

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Abstract

Doped graphene could be of use in next-generation electronic and photonic devices. However, chemical doping cannot be precisely controlled in the material and leads to external disorder that diminishes carrier mobility and conductivity. Here we show that graphene can be efficiently doped using a monolayer of tungsten oxyselenide (TOS) that is created by oxidizing a monolayer of tungsten diselenide. When the TOS monolayer is in direct contact with graphene, a room-temperature mobility of 2,000 cm2 V−1 s−1 at a hole density of 3 × 1013 cm−2 is achieved. Hole density and mobility can also be controlled by inserting tungsten diselenide interlayers between TOS and graphene, where increasing the layers reduces the disorder. With four layers, a mobility value of around 24,000 cm2 V−1 s−1 is observed, approaching the limit set by acoustic phonon scattering, resulting in a sheet resistance below 50 Ω sq−1. To illustrate the potential of our approach, we show that TOS-doped graphene can be used as a transparent conductor in a near-infrared (1,550 nm) silicon nitride photonic waveguide and ring resonator.

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Fig. 1: Electrical and Raman characterization of TOS-doped graphene.
Fig. 2: Structural characterization of monolayer TOS.
Fig. 3: Tuning carrier density and mobilities in TOS-doped graphene with WSe2 interlayers.
Fig. 4: Work-function-mediated charge transfer in TOS-doped graphene.
Fig. 5: Optical properties of TOS-doped graphene.

Data availability

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

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Acknowledgements

We acknowledge fruitful discussions with S. Chae, X. Xu, K. Yao, J. Schuck and E. Hwang, as well as experimental support from L. D’Cruz. This work was primarily supported by the NSF MRSEC Program at Columbia in the Center for Precision-Assembled Quantum Materials (DMR-2011736 and DMR-1420634), in partnership with the National Research Foundation of Korea through the Global Research Laboratory (GRL) program (2016K1A1A2912707) and Research Fellow program (2018R1A6A3A11045864). Device characterization was supported by the National Science Foundation through the CAREER Award (ECCS-1752401). This work was performed in part at the Advanced Science Research Center NanoFabrication Facility at the Graduate Center of the City University of New York and in part at the Columbia Nano Initiative (CNI) Shared Lab Facilities at Columbia University. Synthesis of hBN (K.W. and T.T.) was supported by the MEXT Element Strategy Initiative to Form Core Research Center (grant number JPMXP0112101001) and the CREST(JPMJCR15F3), JST.

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M.S.C., A.N. and Y.J. designed and conducted the initial experiments under the supervision of J.H. and J.T.T. M.S.C. and A.N. stacked, fabricated and conducted the electrical, optical and material characterizations of the samples with B.S.Y.K.’s contribution. B.S.Y.K. established a model for a work-function-mismatch-based doping mechanism. M.E.Z. and X.Z. contributed to the transmittance measurement of CVD samples. I.D. and M. Lipson contributed to the optical loss measurements of TOS-doped graphene integrated into the SiN waveguide. A.B. contributed to the doping study of DNTT. B.K. and D.R. provided flux-grown WSe2 crystals. A.J. and A.N.P. provided the SWCNT grown on SiO2/Si. Z.A.L. and I.K. provided the grown DNTT on TOS. M. Lee contributed to the sample preparation. A.Z. contributed to the transmission electron microscopy, SAED and energy-dispersive X-ray spectroscopy measurements. M.N.N. contributed to the XPS measurements of CVD samples. T.T. and K.W. provided the hBN crystals. W.J.Y. contributed to discussions of the results. M.S.C., A.N. and B.S.Y.K. wrote the manuscript under the supervision of J.H. and J.T.T.

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Correspondence to James Hone or James T. Teherani.

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M.S.C., A.N., A.B., Y.J., J.H. and J.T.T. have filed for a US non-provisional patent application no. 17/236,404 regarding the technology reported in this article. The remaining authors declare no competing interests.

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Choi, M.S., Nipane, A., Kim, B.S.Y. et al. High carrier mobility in graphene doped using a monolayer of tungsten oxyselenide. Nat Electron 4, 731–739 (2021). https://doi.org/10.1038/s41928-021-00657-y

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