Simulation of Electron Spectra for Surface Analysis (SESSA)for quantitative interpretation of (hard) X-ray photoelectron spectra(HAXPES)

Energetic, spatial, and momentum character of the electronic structure at a buried interface: The two-dimensional electron gas between two metal oxides

“…Although the RC for Ti 2p 4+ has a slightly different shape from Gd 4f , this is largely due to the greater difficulty of fitting this weaker peak. The average Ti 3+ /Ti 4+ intensity ratio of ∼7 over the RCs, and measured at both 1181 and 1187 eV before and after the Gd M 5 edge is also qualitatively consistent with the total relative number of these ions in our sample, which is 1 2 , provided that we also allow for the fact that STO is the top layer and is thus enhanced due to photoelectron inelastic scattering; this conclusion has been confirmed using the SESSA program for simulating XPS spectra [30]. An experimental RC for the LHB determined by integrating all intensity over regions B, C, and D as defined in Fig.…”

“…At these energies, the inelastic mean free paths (IMFPs) of the photoelectrons that determine the information depth range in STO(GTO) from 11Å(10Å) at 460 eV to 22Å(20Å) at 1200 eV to 83Å(72Å) at 6000 eV was determined from the TPP-2M formula using the Simulation of Electron Spectra for Surface Analysis (SESSA) program [30], thus permitting us to penetrate into the first buried interface of our multilayer, which is about 20Å below the surface, as shown in Fig. 1(a).…”

Concentration and chemical-state profiles at heterogeneous interfaces with sub-nm accuracy from standing-wave ambient-pressure photoemission

“…The distinction of the peaks from H 2 O(c) and OH À is further justified by examining their different relative intensities through the rocking curve scan (results not shown here). From an analysis of experimental relative core peak intensities using the SESSA XPS simulation program 22,23 the adsorbed water layer is found to be about 5-10 Å thick, although we will later see that the analysis of the SWAPPS results provides a much more accurate value for this thickness of B10 Å. This thickness is significantly larger than that of H 2 O on pure metal oxide surfaces at our relative humidity of B8% (refs 21,24).…”

“…This was done by comparing the relative intensities of all of the peaks shown in Fig. 3a-e, as measured off the Bragg reflection to yield a uniform X-ray flux throughout the sample, with calculated relative intensities from the SESSA XPS simulation program 22,23 . The relevant concentrations in the layer structure of Fig.…”

Understanding the Oxygen Evolution Reaction Mechanism on CoOx using Operando Ambient-Pressure X-ray Photoelectron Spectroscopy

“…These two spectral features are due to the 3d band photoemission of octahedral Evolution of the biphasic catalyst surface structure as a function of the applied potential In order to understand the evolution of the catalyst structure as a function of the applied electrochemical potential, we performed numerical simulations of the photoelectron intensity of the different spectral fitting components forming the measured Co 2p 3/2 core level (see Figure 2c). The numerical simulations were performed using the "Simulation of Electron Spectra for Surface Analysis" (SESSA) software developed by Smekal, Werner, and Powell (62,63). Owing to the conformal nature of the investigated systems, as reported in our previous work (37), continuous layer stacks given by "thickness equivalents" were used to represent the catalyst structure throughout the whole investigation as a function of the applied electrochemical potential.…”