Optically excited (hot) electrons play a crucial role for many fundamental chemical and physical phenomena occurring at surfaces, interfaces, and in bulk materials. They, for instance, determine the properties of photo-induced catalysis at surfaces, and the efficiency of charge and spin transfer across interfaces between different materials. For the investigation of such processes, time-resolved photoelectron spectroscopy did turn out to be a very powerful tool through its direct access to transient band-structure dynamics. In particular, very recent progresses in the development of ultrashort pulsed light sources and electron spectrometers have paved the way for a completely new generation of real-time photoemission techniques. The review concludes with an outlook to the feasibility of future real-time studies in surface and material science.

Bibliography：

Prof. Martin Aeschlimann is a professor of TU Kaiserslautern. He is chair of the State Research Center “Optics and Material Sciences (OPTIMAS)”, head of research facility “Laboratory of Advanced Spin Engineering (LASE)” and chair of the “Condensed Matter Physics” section of the German Physical Societey (DPG).

Prof. Martin Aeschlimann’s research program is devoted to the investigation of ultrafast phenomena in solids, thin films and nanoparticles. This includes the combination of short-pulsed laser systems with surface science technology in order to develop novel methods for measuring ultrafast relaxation processes in real time with high temporal and spatial resolution. Advanced methods used include Time-resolved UV-Photoelectron Spectroscopy, Spin- and Time-resolved Photoemission and Time-resolved Magneto-optial Kerr effect etc.