Electronic conductance and thermopower of single-molecule junctions of oligo(phenyleneethynylene) derivatives

Dekkiche, Hervé; Gemma, Andrea; Tabatabaei, Fatemeh; Batsanov, Andrei S.; Niehaus, Thomas; Gotsmann, Bernd; Bryce, Martin R.

Abstract

We report the synthesis and the single-molecule transport properties of three new oligo(phenyleneethynylene) (OPE3) derivatives possessing terminal dihydrobenzo[b]thiophene (DHBT) anchoring groups and various core substituents (phenylene, 2,5-dimethoxyphenylene and 9,10-anthracenyl). Their electronic conductance and their Seebeck coefficient have been determined using scanning tunneling microscopy-based break junction (STM-BJ) experiments between gold electrodes. The transport properties of the molecular junctions have been modelled using DFT-based computational methods which reveal a specific binding of the sulfur atom of the DHBT anchor to the electrodes. The experimentally determined Seebeck coefficient varies between −7.9 and −11.4 μV K−1 in the series and the negative sign is consistent with charge transport through the LUMO levels of the molecules.

Citation

Dekkiche, H., Gemma, A., Tabatabaei, F., Batsanov, A. S., Niehaus, T., Gotsmann, B., & Bryce, M. R. (2020). Electronic conductance and thermopower of single-molecule junctions of oligo(phenyleneethynylene) derivatives. Nanoscale, 12(36), 18908-18917. https://doi.org/10.1039/d0nr04413j

• Journal Article Type: Article
• Acceptance Date: Aug 31, 2020
• Online Publication Date: Sep 9, 2020
• Publication Date: 2020-09
• Deposit Date: Oct 7, 2020
• Publicly Available Date: Oct 7, 2020
• Journal: Nanoscale
• Print ISSN: 2040-3364
• Electronic ISSN: 2040-3372
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 12
• Issue: 36
• Pages: 18908-18917
• DOI: https://doi.org/10.1039/d0nr04413j