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The electrical conductivity of solution-processed nanosheet networks

Nature Reviews Materials volume 7, pages 217–234 (2022)Cite this article

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Abstract

Solution-processed networks of 2D nanosheets are promising for a range of applications in the field of printed electronics. However, the electrical performance of these networks — represented, for example, by the mobility — is almost always inferior to that of the individual nanosheets. In this Review, we highlight the central role that the inter-sheet junctions play in determining the electrical characteristics of such networks. After briefly reviewing ink formulation and printing methods, we use a selection of electronic applications as examples to demonstrate the dependence of network conductivity on network morphology. We show the network morphology to be heavily influenced by the deposition method, the post-treatment regime and the nanosheet properties. In turn, the morphology of the network fundamentally determines the properties of the inter-sheet junctions, which, ultimately, control the electrical performance of the network. We use reported electrical data to show that three main conduction regimes exist: the network conductivity can be limited by the junctions, by a combination of junction and material properties or, very rarely, by the material properties. Using a meta-analysis of published data, we propose simple models relating network conductivity and mobility to the junction resistance.

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Fig. 1: Exfoliation and inks.
Fig. 2: Nanosheet-network properties.
Fig. 3: Network morphology.
Fig. 4: Nanosheet dimensions.
Fig. 5: Summary of electrical properties of nanosheet networks extracted from the literature.
Fig. 6: Properties affecting junction resistance.

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Acknowledgements

The authors acknowledge the European Research Council Advanced Grant (FUTURE-PRINT) and the European Union under grant agreement no. 785219 Graphene Flagship Core 2. The authors have also received support from the Science Foundation Ireland (SFI) funded centre AMBER (SFI/12/RC/2278). The authors would also like to thank K. Stachura for preparing the graphics in Figs 2 and 6.

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  1. School of Physics, CRANN and AMBER Research Centres, Trinity College Dublin, Dublin, Ireland

    Adam G. Kelly, Domhnall O’Suilleabhain, Cian Gabbett & Jonathan N. Coleman

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All authors researched data for the article; A.G.K. and J.N.C. discussed the content and wrote and edited the manuscript.

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Kelly, A.G., O’Suilleabhain, D., Gabbett, C. et al. The electrical conductivity of solution-processed nanosheet networks. Nat Rev Mater 7, 217–234 (2022). https://doi.org/10.1038/s41578-021-00386-w

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  • DOI: https://doi.org/10.1038/s41578-021-00386-w

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