Modification of self-assembled monolayers by electron irradiation: the effect of primary energy (10-500 eV)
Well-defined alkanethiolate self-assembled monolayers (SAMs) represent a useful model system for a variety of thin organic films on solid supports, in particular in the context of their modification by electron irradiation. Taking a dodecanethiolate SAM on Au(111) as an example, we studied the prima...
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| Hauptverfasser: | , |
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| Dokumenttyp: | Article (Journal) |
| Sprache: | Englisch |
| Veröffentlicht: |
October 26, 2019
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The journal of physical chemistry. C, Energy, materials, and catalysis
Year: 2019, Jahrgang: 123, Heft: 46, Pages: 28301-28309 |
| ISSN: | 1932-7455 |
| DOI: | 10.1021/acs.jpcc.9b09125 |
| Online-Zugang: | Verlag, Volltext: https://doi.org/10.1021/acs.jpcc.9b09125
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| Verfasserangaben: | Martin Schmid, Xianglong Wan, Andika Asyuda, and Michael Zharnikov |
| Zusammenfassung: | Well-defined alkanethiolate self-assembled monolayers (SAMs) represent a useful model system for a variety of thin organic films on solid supports, in particular in the context of their modification by electron irradiation. Taking a dodecanethiolate SAM on Au(111) as an example, we studied the primary electron energy dependence of the respective processes in the range of 10-500 eV. Cross sections of major irradiation-induced processes were derived, including thickness reduction, progressing chemical inhomogeneity, and damage of the SAM-ambient and SAM-substrate interfaces. All of the cross sections showed qualitatively similar behavior as functions of the primary electron energy, viz. a strong, progressive increase in the range of 10-100 eV and a nearly energy-independent character at the higher energies, up to 500 eV. This behavior was primarily attributed to the energy dependence of the ionization cross section, with a certain effect of the secondary electron yield. Quantitatively, the cross sections directly related to irradiation-induced bond breaking followed by desorption or relocation of the released fragments turned out to be noticeably higher (by a factor 2-2.5) than those representing the secondary processes in the SAM, such as reorganization of the SAM and SAM-ambient interface. The balance between the film decomposition, resulting in material loss, and cross-linking, resulting in the preservation of the material, was found to shift toward the decomposition at lower primary electron energies as compared to higher ones. |
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| Beschreibung: | Gesehen am 08.01.2020 |
| Beschreibung: | Online Resource |
| ISSN: | 1932-7455 |
| DOI: | 10.1021/acs.jpcc.9b09125 |