Spontaneous S-Si bonding of alkanethiols to Si(111)-H: Towards Si-molecule-Si circuits

Peiris, CR; Ciampi, S; Dief, EM; Zhang, J; Canfield, PJ; Le Brun, AP; Kosov, DS; Reimers, JR; Darwish, N

Spontaneous S-Si bonding of alkanethiols to Si(111)-H: Towards Si-molecule-Si circuits

Peiris, CR Ciampi, S Dief, EM Zhang, J Canfield, PJ Le Brun, AP Kosov, DS Reimers, JR Darwish, N

Permalink

Publisher:: ROYAL SOC CHEMISTRY
Publication Type:: Journal Article
Citation:: Chemical Science, 2020, 11, (20), pp. 5246-5256
Issue Date:: 2020-05-28

Open Access

Copyright Clearance Process

Recently Added
In Progress
Open Access

This item is open access.

Adobe PDF

Download Published versionAdobe PDF (1.14 MB)

View on publisher's site

View statistics

Full metadata record

Field	Value	Language
dc.contributor.author	Peiris, CR
dc.contributor.author	Ciampi, S
dc.contributor.author	Dief, EM
dc.contributor.author	Zhang, J
dc.contributor.author	Canfield, PJ
dc.contributor.author	Le Brun, AP
dc.contributor.author	Kosov, DS
dc.contributor.author	Reimers, JR
dc.contributor.author	Darwish, N
dc.date.accessioned	2021-01-08T02:59:49Z
dc.date.available	2021-01-08T02:59:49Z
dc.date.issued	2020-05-28
dc.identifier.citation	Chemical Science, 2020, 11, (20), pp. 5246-5256
dc.identifier.issn	2041-6520
dc.identifier.issn	2041-6539
dc.identifier.uri	http://hdl.handle.net/10453/145214
dc.description.abstract	© The Royal Society of Chemistry 2020. We report the synthesis of covalently linked self-assembled monolayers (SAMs) on silicon surfaces, using mild conditions, in a way that is compatible with silicon-electronics fabrication technologies. In molecular electronics, SAMs of functional molecules tethered to goldviasulfur linkages dominate, but these devices are not robust in design and not amenable to scalable manufacture. Whereas covalent bonding to silicon has long been recognized as an attractive alternative, only formation processes involving high temperature and/or pressure, strong chemicals, or irradiation are known. To make molecular devices on silicon under mild conditions with properties reminiscent of Au-S ones, we exploit the susceptibility of thiols to oxidation by dissolved O2, initiating free-radical polymerization mechanisms without causing oxidative damage to the surface. Without thiols present, dissolved O2would normally oxidize the silicon and hence reaction conditions such as these have been strenuously avoided in the past. The surface coverage on Si(111)-H is measured to be very high, 75% of a full monolayer, with density-functional theory calculations used to profile spontaneous reaction mechanisms. The impact of the Si-S chemistry in single-molecule electronics is demonstrated using STM-junction approaches by forming Si-hexanedithiol-Si junctions. Si-S contacts result in single-molecule wires that are mechanically stable, with an average lifetime at room temperature of 2.7 s, which is five folds higher than that reported for conventional molecular junctions formed between gold electrodes. The enhanced “ON” lifetime of this single-molecule circuit enables previously inaccessible electrical measurements on single molecules.
dc.language	English
dc.publisher	ROYAL SOC CHEMISTRY
dc.relation.ispartof	Chemical Science
dc.relation.isbasedon	10.1039/d0sc01073a
dc.rights	info:eu-repo/semantics/openAccess
dc.subject	03 Chemical Sciences
dc.title	Spontaneous S-Si bonding of alkanethiols to Si(111)-H: Towards Si-molecule-Si circuits
dc.type	Journal Article
utslib.citation.volume	11
utslib.for	03 Chemical Sciences
pubs.organisational-group	/University of Technology Sydney/Faculty of Science
pubs.organisational-group	/University of Technology Sydney/Faculty of Science/School of Mathematical and Physical Sciences
pubs.organisational-group	/University of Technology Sydney
utslib.copyright.status	open_access	*
dc.date.updated	2021-01-08T02:59:27Z
pubs.issue	20
pubs.publication-status	Published
pubs.volume	11
utslib.citation.issue	20

Abstract:

© The Royal Society of Chemistry 2020. We report the synthesis of covalently linked self-assembled monolayers (SAMs) on silicon surfaces, using mild conditions, in a way that is compatible with silicon-electronics fabrication technologies. In molecular electronics, SAMs of functional molecules tethered to goldviasulfur linkages dominate, but these devices are not robust in design and not amenable to scalable manufacture. Whereas covalent bonding to silicon has long been recognized as an attractive alternative, only formation processes involving high temperature and/or pressure, strong chemicals, or irradiation are known. To make molecular devices on silicon under mild conditions with properties reminiscent of Au-S ones, we exploit the susceptibility of thiols to oxidation by dissolved O2, initiating free-radical polymerization mechanisms without causing oxidative damage to the surface. Without thiols present, dissolved O2would normally oxidize the silicon and hence reaction conditions such as these have been strenuously avoided in the past. The surface coverage on Si(111)-H is measured to be very high, 75% of a full monolayer, with density-functional theory calculations used to profile spontaneous reaction mechanisms. The impact of the Si-S chemistry in single-molecule electronics is demonstrated using STM-junction approaches by forming Si-hexanedithiol-Si junctions. Si-S contacts result in single-molecule wires that are mechanically stable, with an average lifetime at room temperature of 2.7 s, which is five folds higher than that reported for conventional molecular junctions formed between gold electrodes. The enhanced “ON” lifetime of this single-molecule circuit enables previously inaccessible electrical measurements on single molecules.

Please use this identifier to cite or link to this item:

http://hdl.handle.net/10453/145214