English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Low-energy constraints on photoelectron spectra measured from liquid water and aqueous solutions

MPS-Authors
/persons/resource/persons224796

Malerz,  Sebastian
Molecular Physics, Fritz Haber Institute, Max Planck Society;

/persons/resource/persons242626

Trinter,  Florian
Molecular Physics, Fritz Haber Institute, Max Planck Society;
Institut für Kernphysik, Goethe-Universität;

/persons/resource/persons109362

Hergenhahn,  Uwe
Molecular Physics, Fritz Haber Institute, Max Planck Society;
Leibniz Institute of Surface Engineering (IOM), Department of Functional Surfaces;

Ghrist,  Aaron
Molecular Physics, Fritz Haber Institute, Max Planck Society;
Department of Chemistry, University of Southern California;

/persons/resource/persons222269

Ali,  Hebatallah
Molecular Physics, Fritz Haber Institute, Max Planck Society;
Physics Department, Women Faculty for Art, Science and Education, Ain Shams University;

Richter,  Clemens
Molecular Physics, Fritz Haber Institute, Max Planck Society;
Leibniz Institute of Surface Engineering (IOM), Department of Functional Surfaces;

Lee,  Chin
Molecular Physics, Fritz Haber Institute, Max Planck Society;
Department of Chemistry, University of California;
Chemical Sciences Division, Lawrence Berkeley National Laboratory;

/persons/resource/persons21859

Meijer,  Gerard
Molecular Physics, Fritz Haber Institute, Max Planck Society;

/persons/resource/persons203286

Winter,  Bernd
Molecular Physics, Fritz Haber Institute, Max Planck Society;

External Resource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Malerz, S., Trinter, F., Hergenhahn, U., Ghrist, A., Ali, H., Nicolas, C., et al. (2021). Low-energy constraints on photoelectron spectra measured from liquid water and aqueous solutions. Physical Chemistry Chemical Physics, 23(14), 8246-8260. doi:10.1039/D1CP00430A.


Cite as: http://hdl.handle.net/21.11116/0000-0008-50CF-5
Abstract
We report on the effects of electron collision and indirect ionization processes, occurring at photoexcitation and electron kinetic energies well below 30 eV, on the photoemission spectra of liquid water. We show that the nascent photoelectron spectrum and, hence, the inferred electron binding energy can only be accurately determined if electron energies are large enough that cross sections for quasi-elastic scattering processes, such as vibrational excitation, are negligible. Otherwise, quasi-elastic scattering leads to strong, down-to-few-meV kinetic energy scattering losses from the direct photoelectron features, which manifest in severely distorted intrinsic photoelectron peak shapes. The associated cross-over point from predominant (known) electronically inelastic to quasi-elastic scattering seems to arise at surprisingly large electron kinetic energies, of approximately 10–14 eV. Concomitantly, we present evidence for the onset of indirect, autoionization phenomena (occurring via superexcited states) within a few eV of the primary and secondary ionization thresholds. These processes are inferred to compete with the direct ionization channels and primarily produce low-energy photoelectrons at photon and electron impact excitation energies below ∼15 eV. Our results highlight that vibrational inelastic electron scattering processes and neutral photoexcitation and autoionization channels become increasingly important when photon and electron kinetic energies are decreased towards the ionization threshold. Correspondingly, we show that for neat water and aqueous solutions, great care must be taken when quantitatively analyzing photoelectron spectra measured too close to the ionization threshold. Such care is essential for the accurate determination of solvent and solute ionization energies as well as photoelectron branching ratios and peak magnitudes.