This project is a continuation of a research program to study the modification of solid surfaces by alkali metal overlayers. The effort focuses on investigating the electronic promotion of surface reactions and on the modification of the electronic and atomic structure of several important semiconductors and metals by alkali overlayers and the catalytic oxidation and nitridation of semiconductors. The project is based on technique of photoelectron spectroscopy using the soft x-ray spectrum provided by the high brilliance 1 GeV electron storage ring at the Synchrotron Radiation Center of the University of Wisconsin-Madison. In addition to the electronic properties, information on the atomic structure of investigated interfaces is provided by the use of the relatively new technique of photoemission extended x-ray absorption fine structure. %%% Knowledge of the atomic and electronic structure of metal semiconductor and semiconductor/oxide interfaces is essential to the basic understanding of these systems, as well as for the optimum performance of current and future electronic devices. This project coveres several experimental spectroscopic techniques using existing national resources at the 1 GeV Synchrotron Radiation Center, at the University of Wisconsin-Madison. The work will provide valuable information on the electronic structure, atomic geometry, and the microscopic mechanisms of important catalytic reactions like oxidation or nitridation of the semiconductor and metal surfaces under investigation. The potential impact of this research on the applied and technological areas of metal/semiconductor interfaces is indicated by two recent U.S. patents.
