Modification of alkanethiolate self-assembled monolayers by ultraviolet light: the effect of wavelength
The effect of the wavelength upon the modification of the archetypical nonsubstituted alkanethiolate (AT) self-assembled monolayers (SAMs) on Au(111) by ultraviolet (UV) light was investigated. As a test system, the dodecanethiolate monolayer was selected, while the wavelength of the UV light was va...
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| Main Authors: | , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
January 13, 2021
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| In: |
The journal of physical chemistry. C, Energy, materials, and catalysis
Year: 2021, Volume: 125, Issue: 3, Pages: 1855-1864 |
| ISSN: | 1932-7455 |
| DOI: | 10.1021/acs.jpcc.0c09438 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1021/acs.jpcc.0c09438
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| Author Notes: | Rui Yan, Andreas Terfort, and Michael Zharnikov |
| Summary: | The effect of the wavelength upon the modification of the archetypical nonsubstituted alkanethiolate (AT) self-assembled monolayers (SAMs) on Au(111) by ultraviolet (UV) light was investigated. As a test system, the dodecanethiolate monolayer was selected, while the wavelength of the UV light was varied in two steps from 254 to 375 nm, which is a relevant range for a variety of inexpensive UV sources as well as custom-made and commercial lithography setups. The absolute cross sections of the most prominent and application-relevant UV-induced processes, above all photooxidation of the thiolate anchoring groups to sulfonates, were determined. They were found to decrease exponentially with increasing wavelength, with an effective “wavelength attenuation parameter” of ∼24 nm. This behavior was rationalized within a model assuming the primary role of UV-induced hot electrons, originating from the substrate and triggering an excitation and subsequent oxidation of the sulfur atoms by their reaction with oxygen molecules, penetrating to the SAM-substrate interface across the SAM matrix. The observed behavior and the absolute values of the photooxidation cross sections represent a useful “tool” for the estimation of a proper dose or dose range in the applications involving modification of AT SAMs and thiolate SAMs in general by UV light. |
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| Item Description: | Gesehen am 10.09.2021 |
| Physical Description: | Online Resource |
| ISSN: | 1932-7455 |
| DOI: | 10.1021/acs.jpcc.0c09438 |