Berlin 2018 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 67: Electronic structure of surfaces: Spectroscopy, surface states III

O 67.6: Vortrag

Mittwoch, 14. März 2018, 16:45–17:00, MA 042

First-principles modeling of secondary electron emission from slow ion bombardment — •Marnik Bercx, Bart Partoens, and Dirk Lamoen — EMAT & CMT groups, Department of Physics, University of Antwerp

Secondary electron emission (SEE) is an important phenomenon where electrons of a target material are emitted through the impact of energetic (primary) particles. Such processes lie at the foundation of several techniques for characterizing materials and play an important role in applications such as plasma sputtering deposition or plasma display panels. In our work, we start from the pioneering work of Hagstrum [1] to construct a quantitative model that allows for the determination of the SEE yield from slow ions incident on a surface. We provide a fully ab initio approach by calculating the required input from first-principles Density Functional Theory calculations, as well as making some major conceptual improvements to the model. We further expand the model to include plasmon excitations, which are believed to have a significant effect on the yield spectrum for materials with low plasmon frequencies [2]. The calculated yield spectra, i.e. the kinetic energy distribution of the emitted electrons, are in excellent agreement with experimental results for several semiconductors (Ge, Si) and metals (Al, Mg, Be).