Highly nonlinear transport across single-molecule junctions via destructive quantum interference

Greenwald, J. E., Cameron, J. , Findlay, N. J. , Fu, T., Gunasekaran, S., Skabara, P. J. and Venataraman, L. (2021) Highly nonlinear transport across single-molecule junctions via destructive quantum interference. Nature Nanotechnology, 16, pp. 313-317. (doi: 10.1038/s41565-020-00807-x) (PMID:33288949)

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Abstract

To rival the performance of modern integrated circuits, single-molecule devices must be designed to exhibit extremely nonlinear current–voltage (I–V) characteristics1,2,3,4. A common approach is to design molecular backbones where destructive quantum interference (QI) between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) produces a nonlinear energy-dependent tunnelling probability near the electrode Fermi energy (EF)5,6,7,8. However, tuning such systems is not straightforward, as aligning the frontier orbitals to EF is hard to control9. Here, we instead create a molecular system where constructive QI between the HOMO and LUMO is suppressed and destructive QI between the HOMO and strongly coupled occupied orbitals of opposite phase is enhanced. We use a series of fluorene oligomers containing a central benzothiadiazole10 unit to demonstrate that this strategy can be used to create highly nonlinear single-molecule circuits. Notably, we are able to reproducibly modulate the conductance of a 6-nm molecule by a factor of more than 104.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Skabara, Professor Peter and Cameron, Dr Joseph and Findlay, Dr Neil
Authors: Greenwald, J. E., Cameron, J., Findlay, N. J., Fu, T., Gunasekaran, S., Skabara, P. J., and Venataraman, L.
College/School:College of Science and Engineering > School of Chemistry
Journal Name:Nature Nanotechnology
Publisher:Nature Research
ISSN:1748-3387
ISSN (Online):1748-3395
Published Online:07 December 2020
Copyright Holders:Copyright © 2020 The Authors
First Published:First published in Nature Nanotechnology 16:313–317
Publisher Policy:Reproduced in accordance with the publisher copyright policy
Data DOI:10.5525/gla.researchdata.1062

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
303776Light-controlled manufacturing of semiconductor structures: a platform for next generation processing of photonic devicesPeter SkabaraEngineering and Physical Sciences Research Council (EPSRC)EP/P02744X/2Chemistry
303848Molecular assembly of spintronic circuits with DNAPeter SkabaraEngineering and Physical Sciences Research Council (EPSRC)EP/N035496/2Chemistry