Our mainly experimentally oriented research group is situated both at the South Campus (Institute of Phyical Chemistry) and the North Campus (Institute of Nanotechnology*) of KIT. We study the novel physico-chemical properties of matter constrained to 0.5 - 10 nm dimensions.
One important aspect of our work comprises measurements of the "static" and "dynamic" properties of monodispersed clusters. For example, we probe the electronic and geometric structures of size-selected atomic clusters containing from 3 up to several hundred subunits under isolated ultrahigh vacuum conditions (e.g.: C120 or Fe55-). Additionally, we deposit such species onto well-defined surfaces (and into matrices) using low energy ion beam methods in order to study thermal properties and chemical reactivity. A recent thrust of our research in this area has been the generation of novel cluster assembled materials based on all-carbon building blocks.
Typically our cluster work makes use of ion beam and mass spectrometric methods – a good part of which we develop ourselves leading to unique instrumentation platforms. This has led to an interest in multiply negatively charged molecules in general. For example we are presently studying tunneling autodetachment from electronically excited states of organic chromophore multianions using time-resolved photoelectron spectroscopy and trapped ion laser induced fluorescence. Also, we are studying the conformer distributions of isolated DNA oligonucleotide multianions using a combination of ion mobility and photoelectron spectroscopies.
Beyond surface-bound clusters and cluster assembled materials, we have a long-standing interest in sp2-carbon nanomaterials. For example, we are presently involved in large scale preparation and fractionation of single-walled carbon nanotubes (SWNTs) according to structural type. Furthermore, we study optical (and other electronic) properties, both of purified SWNT materials as well as of individual carbon nanotubes – subject to external physical and chemical perturbations. For this we develop the appropriate spectro(micro)scopic infrastructure as necessary.