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Flexible and transparent all-graphene circuits for quaternary digital modulations

Nature Communications volume 3, Article number: 1018 (2012) | Download Citation

Abstract

In modern communication systems, modulation is a key function that embeds the baseband signal (information) into a carrier wave so that it can be successfully broadcasted through a medium such as air or cables. Here we report a flexible all-graphene modulator circuit with the capability of encoding a carrier signal with quaternary digital information. By exploiting the ambipolarity and the nonlinearity in a graphene transistor, we demonstrate two types of quaternary modulation schemes: quaternary amplitude-shift keying and quadrature phase-shift keying. Remarkably, both modulation schemes can be realized with just 1 and 2 all-graphene transistors, respectively, representing a drastic reduction in circuit complexity when compared with conventional modulators. In addition, the circuit is not only flexible but also highly transparent (~95% transmittance) owing to its all-graphene design with every component (channel, interconnects, load resistor and source/drain/gate electrodes) fabricated from graphene films.

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Acknowledgements

Acknowledgement is made to the National Science Foundation Scalable Nanomanufacturing Program (DMR-1120187). Part of the work was conducted in the Lurie Nanofabrication Facility at University of Michigan, a member of the National Nanotechnology Infrastructure Network funded by the National Science Foundation.

Author information

Affiliations

  1. Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109, USA.

    • Seunghyun Lee
    • , Kyunghoon Lee
    • , Chang-Hua Liu
    • , Girish S. Kulkarni
    •  & Zhaohui Zhong

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Contributions

S.L. and Z.Z. conceived the experiments. S.L. fabricated the devices, developed the electrical measurement set-up and performed the measurements. K.L. provided support for fabrication, C.L. provided support for transmittance measurement, and G.S.K. contributed to the electrical measurement set-up. S.L. wrote the paper and Z.Z. supervised the work. All authors discussed the results and commented on the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Zhaohui Zhong.

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    Supplementary Information

    Supplementary Figures S1-S4, Supplementary Table and Supplementary Reference

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DOI

https://doi.org/10.1038/ncomms2021

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