Daum Group, Technische Universität Clausthal
Understanding physical and chemical interface properties and processes at molecular level is the objective of the research in the group of Prof. Daum. The materials systems under investigation include interfaces of semiconductors as well as of metals and insulators with particular focus on solid-solid and solid-liquid interfaces. Prof. Daum’s contributions to the field of surface nonlinear optics, e. g., surface second-harmonic generation (SHG) and sum-frequency generation (SFG), are internationally recognized. His group is leading in the SHG spectroscopy of semiconductor interfaces. SFG as a spectroscopy of molecular vibrations at interfaces has been applied to study molecular adsorption and reactions at platinum electrode surfaces in aqueous electrolytes as well as the molecular structure of Al2O3 in aqueous environments.
For his research of molecular processes at solid-liquid interfaces using SFG as a vibration spectroscopy Prof. Daum has been awarded a Gerhard Hess research prize of the DFG. Recently, electrochemical scanning tunnelling microscopy (STM) has been successfully established in his group to study chemisorbed layers of atoms and molecules and their potential-controlled structural transformations at platinumelectrolyte interfaces with atomic/molecular resolution. The group has profound expertise in surface electron microscopy (low energy electron microscopy (LEEM), photoemission electron microscopy (PEEM)) which has been used to study catalytic surface properties and processes. The group has attached a tuneable femtosecond laser system to a photoelectron emission microscope and recently demonstrated time- and energy-resolved two-photon photoemission microscopy of dielectric materials systems such as polystyrene.