Once only possible at national labs, near-ambient-pressure XPS is now available at Lehigh University using a new SPECS DeviSim NAP reactor cell coupled with a PHOIBOS 150 NAP electron energy analyzer.

Schematic showing operation of XPS

X-rays from an Al Kα source impinge on the sample through a thin Si3N4 membrane in the environmental cell.  A portion of the photoelectrons enter the electron analyzer through a small aperture. Gas particles are removed by a series of pumps before reaching the detector.  Ionized gas atoms or molecules replenish the electronic charge that has left the surface, mitigating sample charging.


  • In operando measurements of catalysts
  • Characterization of biological materials and other non-vacuum-compatible samples
  • Measurements of surface-gas or surface-liquid interfaces

Sample Preparation

  • In situ gas dosing up to 1 mbar
  • Heating up to 600°C
  • Ar sputter depth profiling

Further Reading


Synonyms and related techniques

  • Electron Spectroscopy for Chemical Analysis (ESCA)
  • Photoemission Spectroscopy (PES)