ABSTRACT

Basic Information

Abstract Number: 2280 - 4
Author Name: Jeff Terry - Illinois Institute of Technology
Session Title: Advanced Surface and Material Analysis by LEIS, XRD, Synchrotron Radiation, XPS, and ToF-SIMS, Individually and Combined
Event Type: Symposia
Event Title: Photoelectron Spectroscopy: From Surface Chemistry To Buried Interfaces

Presider Name:Matthew R Linford
Affiliation:Brigham Young University

Date: Thursday, March 12, 2015
Start Time: 09:45 AM (Slot #4)
Location: 242

Abstract Content

Photoelectron spectroscopy (PES) has been one of the most utilized techniques the for understanding of materials physics and chemistry since its development by Kai Siegbahn for which he received the 1981 Nobel Prize in Physics. In a photoelectron spectroscopy measurement, the kinetic energy of electrons emitted by the sample upon excitation by UV or X-ray photons is measured. This measured quantity is related to the binding energy of the electrons in the material and depends upon the electronic structure of the material. Using photoelectron spectroscopy, one can directly probe the valence electrons in the material, those with binding energy between approximately 0 and -25 eV. These are the electrons involved directly in chemical bonding and are the band states in solids. Measurements as a function of angle, Angle Resolved Photoelectron Spectroscopy (ARPES), allow experimenters to measure the band structure of crystalline solids for comparison with theoretical models. At higher binding energies, the core electrons are observed. These electrons are sensitive to the chemical state of the elements in the material. When the photopeaks are measured at high resolution, fitting of the spectral lines allows for the determination of the chemical bonding and oxidation state of the elements in a material. Using ARPES on the core level peaks, diffraction effects can be used to obtain the local atomic structure of elements in different chemical states. This talk will focus on using PES to elucidate problems of reaction chemistry with examples including chromatography, semiconductor devices, and the nuclear industry.