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...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Taucher, Thomas C. (VerfasserIn) , Hehn, Iris (VerfasserIn) , Hofmann, Oliver T. (VerfasserIn) , Zharnikov, Michael (VerfasserIn) , Zojer, Egbert (VerfasserIn)
Dokumenttyp: Article (Journal)
Sprache:Englisch
Veröffentlicht: January 25, 2016
In: The journal of physical chemistry. C, Energy, materials, and catalysis
Year: 2016, Jahrgang: 120, Heft: 6, Pages: 3428-3437
ISSN:1932-7455
DOI:10.1021/acs.jpcc.5b12387
Online-Zugang:Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1021/acs.jpcc.5b12387
Volltext
Verfasserangaben:Thomas C. Taucher, Iris Hehn, Oliver T. Hofmann, Michael Zharnikov, and Egbert Zojer
Beschreibung
Zusammenfassung: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.
Beschreibung:Gesehen am 20.05.2020
Beschreibung:Online Resource
ISSN:1932-7455
DOI:10.1021/acs.jpcc.5b12387