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A single atom change turns insulating saturated wires into molecular conductors

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Show simple item record Chen, Xiaoping Kretz, Bernhard Adoah, Francis Nickle, Cameron Chi, Xiao Yu, Xiaojiang del Barco, Enrique Thompson, Damien Egger, David A. Nijhuis, Christian A. 2021-07-08T10:06:20Z 2021-07-08T10:06:20Z 2021
dc.description peer-reviewed en_US
dc.description.abstract We present an efficient strategy to modulate tunnelling in molecular junctions by changing the tunnelling decay coefficient, β, by terminal-atom substitution which avoids altering the molecular backbone. By varying X = H, F, Cl, Br, I in junctions with S(CH2)(10-18)X, current densities (J) increase >4 orders of magnitude, creating molecular conductors via reduction of β from 0.75 to 0.25 Å−1. Impedance measurements show tripled dielectric constants (εr) with X = I, reduced HOMO-LUMO gaps and tunnelling-barrier heights, and 5-times reduced contact resistance. These effects alone cannot explain the large change in β. Density functional theory shows highly localized, X-dependent potential drops at the S(CH2)nX// electrode interface that modifies the tunnelling barrier shape. Commonly-used tunnelling models neglect localized potential drops and changes in εr. en_US
dc.language.iso eng en_US
dc.publisher Nature Research en_US
dc.relation MOE2019-T2-1-137 en_US
dc.relation.ispartofseries Nature Communications;12, 3432
dc.subject tunnelling en_US
dc.subject electrode en_US
dc.title A single atom change turns insulating saturated wires into molecular conductors en_US
dc.type info:eu-repo/semantics/article en_US
dc.type.supercollection all_ul_research en_US
dc.type.supercollection ul_published_reviewed en_US
dc.identifier.doi 10.1038/s41467-021-23528-8
dc.contributor.sponsor Ministry of Education en_US
dc.rights.accessrights info:eu-repo/semantics/openAccess en_US

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