The high-brilliance X-ray source PETRA III & Photoelectron spectroscopy with hard X-rays

The 3rd generation storage ring PETRA III at DESY (Hamburg, Germany) is a powerful high-brilliance X-ray source for a wide range of analytical techniques in materials science. The current status of the facility will be presented highlighting recent scientific results. An overview will be given on the upcoming extension project which will complement the experimental possibilities. The high source brilliance is especially suited for flux-hungry high-resolution X-ray spectroscopy techniques. As an example, the use of X-ray excitation in the range 3 to 12 keV for photoelectron spectroscopy will be discussed. This "HAXPES" method is a powerful tool to study electronic structure of (as-grown) complex materials and buried nano-structures or multi-layered interfaces. The key factor is a much larger mean electron free path (compared to standard XPS) resulting in electron escape depths of some 10nm. The particular characteristics of this approach will be discussed and an overview will be given on the current state of the technique, highlighting its great potential by recent scientific results.