Auger Electron Spectroscopy (AES)

In an experiment AES atoms in a specimen also become ionised as a result of photoelectron emission; in this state the atomic structure contains an excess of energy after the photoelectron emission from the core levels, and will be relaxed by Auger electron emission. Each element produces a characteristic set of Auger peaks that indicates its presence. This technique is an efficient means for filling core holes of low binding energy, thus giving rise to relatively low kinetic energy Auger electrons with a short mean free path. Their detection outside the solid therefore provides a surface sensitive profile of elemental composition. In fact, this technique is the dominat mechanism for light elements, whereas XPS dominates for heavy elements.