Open AccessUnified treatment of recoil and Doppler broadening in molecular high-energy photoemission
Author(s) -
E. Kukk,
Denis Céolin,
Oksana Travnikova,
R. Püttner,
Maria Novella Piancastelli,
R. Guillemin,
L. Journel,
T. Marchenko,
Iyas Ismail,
Jessica B. Martins,
J. P. Rueff,
M. Simon
Publication year - 2021
Publication title -
new journal of physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.584
H-Index - 190
ISSN - 1367-2630
DOI - 10.1088/1367-2630/ac08b4
Subject(s) - recoil , physics , doppler broadening , atomic physics , spectral line , doppler effect , diatomic molecule , inverse photoemission spectroscopy , photon , kinetic energy , electron , synchrotron , photoemission spectroscopy , molecule , nuclear physics , optics , quantum mechanics
Doppler and recoil effects are an integral part of the photoemission process at the high kinetic energies reached in hard x-ray photo-electron spectroscopy (HAXPES) and have a major effect on the observed lineshape, resulting in broadening, energy losses and discrete excitations. These effects can be modeled with a high degree of detail for small systems like diatomic molecules, for larger systems such treatment is often superfluous as the fine spectral features are not observable. We present a united description of the Doppler and recoil effects for arbitrary polyatomic systems and offer an approximate description of the recoil- and Doppler-modified photoemission spectral lineshape as a practical tool in the analysis of HAXPES spectra of core-level photoemission. The approach is tested on the examples of carbon dioxide and pentane molecules. The C and O 1s photoelectron spectra of CO 2 in gas phase were also measured at 2.3 and 7.0 keV photon energy at Synchrotron SOLEIL and the spectra were analyzed using the model description. The limitations and applicability of the approach to adsorbates, interfaces and solids is briefly discussed.