AVS 59th Annual International Symposium and Exhibition
    Applied Surface Science Monday Sessions
       Session AS-MoM

Paper AS-MoM3
Simulation of Electron Spectra for Surface Analysis (SESSA): (Hard) X-ray Photoelectron Spectra of Nanostructured Surfaces

Monday, October 29, 2012, 9:00 am, Room 20

Session: Quantitative Surface Chemical Analysis, Technique Development, and Data Interpretation - Part 1
Presenter: W.S.M. Werner, Vienna University of Technology, Austria
Authors: W.S.M. Werner, Vienna University of Technology, Austria
W. Smekal, Vienna University of Technology, Austria
C.J. Powell, National Institute of Standards and Technology
Correspondent: Click to Email
The National Institute of Standards and Technology (NIST) Database for the Simulation of Electron Spectra for Surface Analysis (SESSA) [1,2] has been modified to allow a user to simulate XPS spectra of nanostructured surfaces, such as surfaces covered with rectangular islands, pyramids, spheres, layered spheres, etc. The effect of the nanomorhphology of the surface on the emitted angular and energy distribution of photoelectrons is investigated. Comparison with simple models in the literature, which neglect several aspects of the physics of signal generation, such as elastic electron scattering, the dependence of the inelastic mean free path of the position of the electron in the specimen, the anisotropy of the photoelectric cross section, etc. gives good agreement when the same model assumptions are made in the simulations, but show significant deviations for more physically realistic simulations. The extent to which information on the nanomorphology can be extracted from the photoelectron angular/energy distribution is investigated, in particular the question is addressed whether the average size of nanostructures on a surface is accessible by means of analysis of angular/energy photoelectron spectra. This is done for standard AlKα and Mg Kα laboratory sources, but the possibility to gain additional information by increasing the photon energy to the hard x-ray regime is also examined.

1. http://www.nist.gov/srd/nist100.cfm.

2. W. Smekal, W. S. M. Werner, and C. J. Powell, Surf. Interface Anal. 37, 1059 (2005).