Electron Transfer Reactions at Interfaces

Electron injection from a molecular donor orbital into empty electronic acceptor states of a solid is often referred to as heterogeneous electron transfer (HET). HET is of great significance in many different contexts ranging from condensed matter physics to biology. Since more than two decades there has been a continuing effort towards developing the field of molecular electronics, where HET will play a key role. HET has been studied in nano-hybrid systems aiming at practical applications like solar-cells. Since HET reveals unique properties of the electron transfer process, it can be considered also as a research topic in its own right. We are employing and developing ultrafast time-resolved techniques to study HET in real time and gain direct access to parameters governing the transfer reaction.

Charge Carrier Dynamics in Nanomaterials

Measurements that are performed on a large ensemble of particles demand a high degree of homogeneity to gain meaningful results. A better way of reducing the effect of broad distributions in sample properties is by monitoring single particles, or measuring single molecules. To achieve this, we developed an ultrafast time-resolved Kerr-gated fluorescence microscope. Application of this technique to charge carrier dynamics in CdSSe semiconductor nanowires let to a detailed understanding of the underlying dynamics that was formerly hidden in the ensemble average. We are improving and expanding this technique and applying it to a wide range of technological important materials.