Surface Analysis Lab

Description:
Photoelectron spectroscopy is a surface analysis tool for chemical and electronic characterization of materials. Its distinguishing feature is the possibility to measure chemical states. The information depth is 1-9 nm. The technique relies on the photoelectric effect. The photoexcitation energies typically range from ~20 eV (UPS) to ~1.5 keV (XPS). The photoelectrons are filtered regarding their kinetic energy by the analyser and counted by the detector. The lower the kinetic energy of the photoelectron, the more tightly it was bound to the nucleus, so the higher is its binding energy. Besides chemical information, also electrostatic potentials at surfaces and interfaces can be studied.