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Carrier generation and electronic properties of a single-component pure organic metal

Nature Materials volume 16, pages 109–114 (2017)Cite this article

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A Corrigendum to this article was published on 01 September 2017

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Abstract

Metallic conduction generally requires high carrier concentration and wide bandwidth derived from strong orbital interaction between atoms or molecules. These requisites are especially important in organic compounds because a molecule is fundamentally an insulator; only multi-component salts with strong intermolecular interaction—namely, only charge transfer complexes and conducting polymers—have demonstrated intrinsic metallic behaviour. Herein we report a single-component electroactive molecule, zwitterionic tetrathiafulvalene(TTF)-extended dicarboxylate radical (TED), exhibiting metallic conduction even at low temperatures. TED exhibits d.c. conductivities of 530 S cm−1 at 300 K and 1,000 S cm−1 at 50 K with copper-like electronic properties. Spectroscopic and theoretical investigations of the carrier-generation mechanism and the electronic states of this single molecular species reveal a unique electronic structure with a spin-density gradient in the extended TTF moieties that becomes, in itself, a metallic state.

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Figure 1: Molecular structure of zwitterionic tetrathiafulvalene-extended dicarboxylate radical (TED).
Figure 2: Electronic properties of TED.
Figure 3: Spectroscopic analyses for carrier generation in TED.
Figure 4: Structural and optical properties of TED.

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Change history

  • 09 August 2017

    In the version of this Article originally published, the sign of each x-axis value in Fig. 2d and its inset was incorrect. This has been corrected in the online version. This change does not affect the results of the paper.

  • 01 September 2017

    Nature Materials 16, 109–114 (2017); published online 10 October 2016; corrected after print 9 August 2017 In the version of this Article originally published, the sign of each x-axis value in Fig. 2d and its inset was incorrect. This has been corrected in the online version and the correct panel isshown here.

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Acknowledgements

We acknowledge C. Kloc (NTU), J. Hui (NTU) and T. Nakamura (IMS) for fruitful discussions. We also thank Y. Ide (NIMS), C. Nishimura (NIMS), M. Sumiya (NIMS), K. Tashiro (NIMS), H. Yoshikawa (NIMS) and M. Ohnuma (Hokkaido University) for discussions and technical support. We acknowledge S. Kurosawa (NIMS) and M. Takahashi (NIMS) for assistance in sample preparation and physical measurements. This study was partially supported by the ‘NEXT’ Program of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan, and Nano-Integration Foundry and the ‘Low-Carbon Research Network’ in NIMS.

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Author notes

  1. Takeshi Terauchi

    Present address: Present address: Department of Chemistry, Tohoku University, Aoba 6-3, Sendai 980-8578, Japan.,

Authors and Affiliations

  1. Research Center for Functional Materials, National Institute for Materials Science (NIMS), Sengen 1-2-1, Tsukuba 305-0047, Japan

    Yuka Kobayashi, Takeshi Terauchi & Satoshi Sumi

  2. Materials Analysis Station, National Institute for Materials Science (NIMS), Sengen 1-2-1, Tsukuba 305-0047, Japan

    Yoshitaka Matsushita

Authors
  1. Yuka Kobayashi
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Contributions

Y.K. and T.T. prepared the materials. Y.K. carried out spectroscopic analyses and MO calculations. Y.K. and S.S. measured transport properties. Y.M. carried out XRD analysis. Y.K. conceived the project and wrote the manuscript.

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Correspondence to Yuka Kobayashi.

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Kobayashi, Y., Terauchi, T., Sumi, S. et al. Carrier generation and electronic properties of a single-component pure organic metal. Nature Mater 16, 109–114 (2017). https://doi.org/10.1038/nmat4768

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