Understanding chemical versus electrostatic shifts in X-ray photoelectron spectra of organic self-assembled monolayers
The focus of the present article is on understanding the insight that X-ray photoelectron spectroscopy (XPS) measurements can provide when studying self-assembled monolayers. Comparing density functional theory calculations to experimental data on deliberately chosen model systems, we show that both...
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| Main Authors: | , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
January 25, 2016
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| In: |
The journal of physical chemistry. C, Energy, materials, and catalysis
Year: 2016, Volume: 120, Issue: 6, Pages: 3428-3437 |
| ISSN: | 1932-7455 |
| DOI: | 10.1021/acs.jpcc.5b12387 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1021/acs.jpcc.5b12387
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| Author Notes: | Thomas C. Taucher, Iris Hehn, Oliver T. Hofmann, Michael Zharnikov, and Egbert Zojer |
| Summary: | The focus of the present article is on understanding the insight that X-ray photoelectron spectroscopy (XPS) measurements can provide when studying self-assembled monolayers. Comparing density functional theory calculations to experimental data on deliberately chosen model systems, we show that both the chemical environment and electrostatic effects arising from a superposition of molecular dipoles influence the measured core-level binding energies to a significant degree. The crucial role of the often overlooked electrostatic effects in polar self-assembled monolayers (SAMs) is unambiguously demonstrated by changing the dipole density through varying the SAM coverage. As a consequence of this effect, care has to be taken when extracting chemical information from the XP spectra of ordered organic adsorbate layers. Our results, furthermore, imply that XPS is a powerful tool for probing local variations in the electrostatic energy in nanoscopic systems, especially in SAMs. |
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| Item Description: | Gesehen am 20.05.2020 |
| Physical Description: | Online Resource |
| ISSN: | 1932-7455 |
| DOI: | 10.1021/acs.jpcc.5b12387 |