Field-induced Conductance Switching by Charge-state Alternation in Organometallic Single-Molecule Junctions

Charge transport through single molecules can be influenced by the charge and spin states of redox-active metal centres placed in the transport pathway. These molecular intrinsic properties are usually addressed by varying the molecules electrochemical and magnetic environment, a procedure that requ...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2016-09
Main Authors: Schwarz, Florian, Kastlunger, Georg, Lissel, Franziska, Egler-Lucas, Carolina, Semenov, Sergey N, Venkatesan, Koushik, Berke, Heinz, Stadler, Robert, Loertscher, Emanuel
Format: Article
Language:English
Subjects:
Charge transport
Electric fields
Electric potential
Electrical junctions
Hysteresis
Low currents
Magnetic properties
Molecular orbitals
Organometallic compounds
Oxidation
Resistance
Switching
Transport buildings, stations and terminals
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Charge transport through single molecules can be influenced by the charge and spin states of redox-active metal centres placed in the transport pathway. These molecular intrinsic properties are usually addressed by varying the molecules electrochemical and magnetic environment, a procedure that requires complex setups with multiple terminals. Here we show that oxidation and reduction of organometallic compounds containing either Fe, Ru or Mo centres can solely be triggered by the electric field applied to a two-terminal molecular junction. Whereas all compounds exhibit bias-dependent hysteresis, the Mo-containing compound additionally shows an abrupt voltage-induced conductance switching, yielding high to low current ratios exceeding 1000 at voltage stimuli of less than 1.0 V. DFT calculations identify a localized, redox active molecular orbital that is weakly coupled to the electrodes and closely aligned with the Fermi energy of the leads because of the spin-polarised ground state unique to the Mo centre. This situation opens an additional slow and incoherent hopping channel for transport, triggering a transient charging effect of the entire molecule and a strong hysteresis with unprecedented high low-to-high current ratios.
ISSN:2331-8422
DOI:10.48550/arxiv.1609.01200