Angle-resolved measurements of the photoemission of electrons in the study of solids

Abstract

Angle-resolved photoemission is shown to be a very versatile technique which probes electronic structure as well as geometric structure. All quantum numbers of an electronic state can be determined. In particular, energy and momentum of electrons in a solid are probed by measuring energy and momentum of photoelectrons. Thus, energy versus momentum band dispersions can be measured. Since photoelectrons have a small but tunable escape depth, it is possible to see surface and adsorbate states as well as bulk states. A completely different application of angle-resolved photoemission concerns the atomic positions and bond orientations at surfaces. Photoelectrons from a well-defined atom serve as source for an electron diffraction experiment which is localized to a surface. Another type of experiment uses the emission pattern from adsorbed molecules to determine their orientation. © Taylor & Francis Group, LLC.