Monte-Carlo simulation of x-ray photoelectron emission from silver

Silver 3d x-ray photoelectron spectroscopy (XPS) spectra were simulated with the Monte-Carlo method using an effective energy-loss function that was derived from a reflected electron energy-loss spectroscopy (REELS) analysis based on an extended Landau approach. After confirming that Monte-Carlo simulation based on the use of the effective energy-loss function can successfully describe the experimental REELS spectrum and Ag 3d XPS spectrum, we applied Monte-Carlo simulation to predict the angular distribution of Ag 3d x-ray photoelectrons for different x-ray incidence angles and different photoelectron take-off angles. The experimental photoelectron emission microscope that we are constructing was confirmed as being close to the optimum configuration, in which the x-ray incident angle as measured from the surface normal direction is 74degrees and the photoelectron take-off angle is set normal to the surface. The depth distribution functions of the Ag 3d X-ray photoelectrons for different energy windows suggest that the photoelectron emission microscope will exhibit greater surface sensitivity for narrower photoelectron energy windows. Copyright (C) 2003 John Wiley Sons, Ltd.