One of the main challenges to upscale the fabrication of molecular devices is to achieve a mechanically stable device with reproducible and controllable electronic features that operates at room temperature1,2. This is crucial because structural and electronic fluctuations can lead to significant changes in the transport characteristics at the electrode–molecule interface3,4. In this study, we report on the realization of a mechanically and electronically robust graphene-based molecular junction. Robustness was achieved by separating the requirements for mechanical and electronic stability at the molecular level. Mechanical stability was obtained by anchoring molecules directly to the substrate, rather than to graphene electrodes, using a silanization reaction. Electronic stability was achieved by adjusting the π–π orbitals overlap of the conjugated head groups between neighbouring molecules. The molecular devices exhibited stable current–voltage (I–V) characteristics up to bias voltages of 2.0 V with reproducible transport features in the temperature range from 20 to 300 K.
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The data that support the plots within this paper and other findings of this study are available from the corresponding authors upon reasonable request. Measurements and analysis were performed in Origin and Matlab. All codes are available from the authors upon reasonable request.
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We thank C. Schönenberger for fruitful discussions. This work was partially supported by the European Commission FP7-ITN Molecular-scale Electronics: Concepts, Contacts and Stability (MOLESCO) grant (no. 606728) and the FET open project QuIET (no. 767187). This work was supported by UK Engineering and Physical Sciences Research Council Grant EP/M014452/1 and EP/N017188/1 and the European Research Council Advanced Grant (Mols@Mols). H.S. acknowledges the UK Research and Innovation for Future Leaders Fellowship no. MR/S015329/1 and the Leverhulme Trust for Leverhulme Early Career Fellowship no. ECF-2017-186. S.S. acknowledges the Leverhulme Trust for Early Career Fellowship no. ECF-2018-375. M.L.P. acknowledges the funding by the EMPAPOSTDOCS-II programme, which has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska–Curie Grant Agreement no. 754364. O.B. acknowledges technical support from the Binning and Rohrer Nanotechnology Center (BRNC).
The authors declare no competing interests.
Peer review information Nature Nanotechnology thanks Dirk Mayer and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
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El Abbassi, M., Sangtarash, S., Liu, X. et al. Robust graphene-based molecular devices. Nat. Nanotechnol. 14, 957–961 (2019). https://doi.org/10.1038/s41565-019-0533-8
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