AG Wucher - Research
Research Interests
The main research interest of this group is applied surface science, with emphasis on problems with relevance to material science. The fields of work in particular are:
Our group conducts fundamental research regarding the interaction between high-energy particles and solid surfaces, particularly ion-induced particle emission, but also sputtering-induced changes to the stoichiometry and structure of surfaces. Among others, we use laser-based methods for the state-sensitive detection of unleashed particles. A decisive factor regarding fundamental research is also the availability of electron-based and mass spectrometric techniques that can determine the chemical and structural properties of surfaces and thin-films. Thus, research and development in the field of modern surface and thin-film analysis is one of the central points of our group. Particularly the laser-based secondary neutral particle mass spectrometry (SNMS), which is used as a method for the analysis of the chemical composition of solid surfaces and thin-films on a microscopic scale is applied.
Fig. 1. Schematic buildup of a laser-based secondary neutral particle microprobe. Neutral atoms and molecules sputtered by ion impact are post-ionized by an intense pulsed laser so that they can be detected by the mass spectrometer.
Characteristic for the study of particle-surface interaction and for surface and thin film analysis is the need for an extremely high vaccum ("ultrahigh vacuum" UHV) with pressures down to 10-10 mbar. In Fig. 2, an ultrahigh vacuum chamber is pictured, in which a time-of-flight mass spectrometer and a high-focused liquid metal ion gun are combined into a device that can detect sputtered neutral particles.
Fig. 2. Ultrahigh vacuum chamber for the study of particle-surface interactions.
The research conducted by this group is mainly part of projects supported by the German Research Foundation (Deutsche Forschungsgemeinschaft).