ABSTRACT Solid-state molecular tunnel junctions are often assumed to operate in the Landauer regime, which describes essentially activationless coherent tunnelling processes. In solution, on

the other hand, charge transfer is described by Marcus theory, which accounts for thermally activated processes. In practice, however, thermally activated transport phenomena are frequently

observed also in solid-state molecular junctions but remain poorly understood. Here, we show experimentally the transition from the Marcus to the inverted Marcus region in a solid-state

molecular tunnel junction by means of intra-molecular orbital gating that can be tuned via the chemical structure of the molecule and applied bias. In the inverted Marcus region, charge

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INTO MOLECULAR CONDUCTORS Article Open access 08 June 2021 ELIMINATION OF CHARGE-CARRIER TRAPPING BY MOLECULAR DESIGN Article Open access 29 June 2023 TRANSIENTLY DELOCALIZED STATES ENHANCE

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J. et al. _Gaussian 09, revision D.01_. (Gaussian, Inc., Wallingford CT, 2013). Google Scholar  Download references ACKNOWLEDGEMENTS L.Y., L.J.W., L.J., H.V.A. and C.A.N. acknowledge the

Ministry of Education (MOE) for supporting this research under award no. MOE2015-T2-1-050, and the National Research Foundation, Prime Minister’s Office, Singapore, under its Medium-sized

Centre Program. A.R.G., M.A.A. and E.B. acknowledge support from the National Science Foundation (grants NSF-ECCS #1402990 and #1518863). Yu Xiaojiang is kindly acknowledged for assisting at

the SINS beam line at SSLS under NUS core support C-380-003-003-001. AUTHOR INFORMATION Author notes * Lejia Wang Present address: School of Materials and Chemical Engineering, Ningbo

University of Technology, Ningbo, China * These authors contributed equally: Li Yuan, Lejia Wang and Alvar R. Garrigues. AUTHORS AND AFFILIATIONS * Department of Chemistry, National

University of Singapore, Singapore, Singapore Li Yuan, Lejia Wang, Li Jiang, Harshini Venkata Annadata & Christian A. Nijhuis * Department of Physics, University of Central Florida,

Orlando, Florida, USA Alvar R. Garrigues, Marta Anguera Antonana & Enrique Barco * Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore,

Singapore, Singapore Christian A. Nijhuis * NUSNNI-Nanocore, National University of Singapore, Singapore, Singapore Christian A. Nijhuis Authors * Li Yuan View author publications You can

also search for this author inPubMed Google Scholar * Lejia Wang View author publications You can also search for this author inPubMed Google Scholar * Alvar R. Garrigues View author

publications You can also search for this author inPubMed Google Scholar * Li Jiang View author publications You can also search for this author inPubMed Google Scholar * Harshini Venkata

Annadata View author publications You can also search for this author inPubMed Google Scholar * Marta Anguera Antonana View author publications You can also search for this author inPubMed 

Google Scholar * Enrique Barco View author publications You can also search for this author inPubMed Google Scholar * Christian A. Nijhuis View author publications You can also search for

this author inPubMed Google Scholar CONTRIBUTIONS L.J.W. synthesized and characterized the ferrocene-based molecules. L.Y. conducted the temperature-dependent measurements and characterized

the ferrocene-based SAMs. L.J. performed the charge transport measurements at room temperature. H.V.A. performed the DFT calculations. A.R.G. conducted the single-molecule transport

measurements and fitted the data to a double quantum dot model. M.A.A. assisted with the single-molecule measurements. E.B. supervised the single-molecule experiments and fitted the SAMs

data. C.A.N. conceived and supervised the project. All the authors contributed to the writing of the article and interpretation of the results. CORRESPONDING AUTHORS Correspondence to

Enrique Barco or Christian A. Nijhuis. ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing interests. ADDITIONAL INFORMATION PUBLISHER’S NOTE: Springer Nature remains

neutral with regard to jurisdictional claims in published maps and institutional affiliations. SUPPLEMENTARY INFORMATION SUPPLEMENTARY INFORMATION Supplementary Figures 1–43, Supplementary

Tables 1–4, Supplementary Methods, Supplementary discussions. RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Yuan, L., Wang, L., Garrigues, A.R. _et

al._ Transition from direct to inverted charge transport Marcus regions in molecular junctions via molecular orbital gating. _Nature Nanotech_ 13, 322–329 (2018).

https://doi.org/10.1038/s41565-018-0068-4 Download citation * Received: 03 April 2017 * Accepted: 17 January 2018 * Published: 26 March 2018 * Issue Date: April 2018 * DOI:

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