XPS and UPS Background

This will house a background description of the technique and methodologies for photoelectron spectroscopy. For the time being, look at the MMRC pages maintained by Bruce Brunschwig at Caltech.

Boilerplate text for manuscripts

The text below may serve as a good starting point for the XPS acquisition detail in a manuscript.  The specifics may change based on whether charge neutralization was or was not employed, whether non-standard acquisition steps/pass energies were employed, what specific regions were collected, and how the data in those regions were fit.  Contact Grimm if you have any questions.

A PHI5600 XPS system with a third-party data acquisition system (RBD Instruments, Bend Oregon) acquired all photoelectron spectra as detailed previously.# Analysis chamber base pressures were <1 × 10−9 Torr. A hemispherical energy analyzer that was positioned at 90° with respect to the incoming monochromated Al Kα X-ray flux and 45° with respect to standard sample positioning collected the photoelectrons. Survey spectra utilized a 117 eV pass energy, a 0.5 eV step size, and a 50-ms-per-step dwell time. High-resolution XP spectra employed a 23.5 eV pass energy, 0.025 eV step size, and a 50 ms dwell time per step. Based on a consistent 285 eV position of features ascribed to adventitious carbon, acquisitions did not necessitate charge neutralization.*  Post-acquisition data fitting employed W-Tougaard-style baselines and GL(70) peak shapes for features within the Cs 3d, I 3d, Sn 3d; a Shirley-style baseline and GL(70) peak shape within the Pb 4f region; a W-Tougaard baseline and GL(30) peak shape for Br 3d and N 1s regions; and linear baselines with GL(30) peak shapes for B 1s, C 1s, F 1s, and O 1s regions. Fits that employ multiple peaks within a spectral region utilized identical fwhm values for each peak to minimize mathematically optimized but possibly chemically unrealistic fits.

# Cite the first manuscript from the group that described the XPS instrument, 10.1021/acsami.7b07117.

* If charge neutralization was employed, talk to Grimm.