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Postadsorption Work Function Tuning via Hydrogen Pressure Control

[Image: see text] The work function of metal substrates can be easily tuned, for instance, by adsorbing layers of molecular electron donors and acceptors. In this work, we discuss the possibility of changing the donor/acceptor mixing ratio reversibly after adsorption by choosing a donor/acceptor pai...

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Autores principales: Edlbauer, Hermann, Zojer, Egbert, Hofmann, Oliver T.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2015
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4671103/
https://www.ncbi.nlm.nih.gov/pubmed/26692915
http://dx.doi.org/10.1021/acs.jpcc.5b08827
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author Edlbauer, Hermann
Zojer, Egbert
Hofmann, Oliver T.
author_facet Edlbauer, Hermann
Zojer, Egbert
Hofmann, Oliver T.
author_sort Edlbauer, Hermann
collection PubMed
description [Image: see text] The work function of metal substrates can be easily tuned, for instance, by adsorbing layers of molecular electron donors and acceptors. In this work, we discuss the possibility of changing the donor/acceptor mixing ratio reversibly after adsorption by choosing a donor/acceptor pair that is coupled via a redox reaction and that is in equilibrium with a surrounding gas phase. We discuss such a situation for the example of tetrafluoro-1,4-benzenediol (TFBD)/tetrafluoro-1,4-benzoquinone (TFBQ), adsorbed on Cu(111) and Ag(111) surfaces. We use density functional theory and ab initio thermodynamics to show that arbitrary TFBD/TFBQ mixing ratios can be set using hydrogen pressures attainable in low to ultrahigh vacuum. Adjusting the mixing ratio allows modifying the work function over a range of about 1 eV. Finally, we contrast single-species submonolayers with mixed layers to discuss why the resulting inhomogeneities in the electrostatic energy above the surface have different impacts on the interfacial level alignment and the work function.
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spelling pubmed-46711032015-12-09 Postadsorption Work Function Tuning via Hydrogen Pressure Control Edlbauer, Hermann Zojer, Egbert Hofmann, Oliver T. J Phys Chem C Nanomater Interfaces [Image: see text] The work function of metal substrates can be easily tuned, for instance, by adsorbing layers of molecular electron donors and acceptors. In this work, we discuss the possibility of changing the donor/acceptor mixing ratio reversibly after adsorption by choosing a donor/acceptor pair that is coupled via a redox reaction and that is in equilibrium with a surrounding gas phase. We discuss such a situation for the example of tetrafluoro-1,4-benzenediol (TFBD)/tetrafluoro-1,4-benzoquinone (TFBQ), adsorbed on Cu(111) and Ag(111) surfaces. We use density functional theory and ab initio thermodynamics to show that arbitrary TFBD/TFBQ mixing ratios can be set using hydrogen pressures attainable in low to ultrahigh vacuum. Adjusting the mixing ratio allows modifying the work function over a range of about 1 eV. Finally, we contrast single-species submonolayers with mixed layers to discuss why the resulting inhomogeneities in the electrostatic energy above the surface have different impacts on the interfacial level alignment and the work function. American Chemical Society 2015-11-09 2015-12-03 /pmc/articles/PMC4671103/ /pubmed/26692915 http://dx.doi.org/10.1021/acs.jpcc.5b08827 Text en Copyright © 2015 American Chemical Society This is an open access article published under a Creative Commons Attribution (CC-BY) License (http://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.html) , which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited.
spellingShingle Edlbauer, Hermann
Zojer, Egbert
Hofmann, Oliver T.
Postadsorption Work Function Tuning via Hydrogen Pressure Control
title Postadsorption Work Function Tuning via Hydrogen Pressure Control
title_full Postadsorption Work Function Tuning via Hydrogen Pressure Control
title_fullStr Postadsorption Work Function Tuning via Hydrogen Pressure Control
title_full_unstemmed Postadsorption Work Function Tuning via Hydrogen Pressure Control
title_short Postadsorption Work Function Tuning via Hydrogen Pressure Control
title_sort postadsorption work function tuning via hydrogen pressure control
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4671103/
https://www.ncbi.nlm.nih.gov/pubmed/26692915
http://dx.doi.org/10.1021/acs.jpcc.5b08827
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