Abstract

We will present our basic ideas for combining different types of materials in layer-type and bulk composite structures for advanced functional devices. In such devices, the interfaces between the different materials dominate the performance. First the experimental approach will be presented, which uses integrated UHV preparation and analysis chambers (cluster tools) and allows to combine different synthesis procedures and sophisticated surface analytical tools down to the atomic level. Then some typical research areas will be presented such as:

1. Van der Waals-like passivation layers of Silicon surfaces aiming at the integration of an extra function to Silicon microelectronics. These stable chemical buffer layers allow the deposition of metallic contact layers, and inorganic or organic deposits avoiding chemical interface reactions. Interestingly the contact potential distribution can be strongly modified by the intermediate layer depending on the dipole layers introduced at the interface.

2. Inorganic/organic semiconductor composites will be presented as novel and promising optoelectronic devices. In contrast to other approaches, organic dye is incorporated as a guest material in the inorganic semiconductor host in our structures. The synthetic routes and properties of these composites will be discussed for their possible use in solar cells and LED’s.

3. Finally, we will discuss the use of surface science techniques to investigate electrochemical (wet) processes. As examples, dye injection type solar cells and modification of the surface properties of semiconductor heterostructures will be presented.

Biography

Wolfram Jaegermann studied Chemistry at the University of Dortmund and got his Ph.D. in Inorganic Chemistry from the University of Bielefeld, Germany. He started his scientific career as a Post-Doc in the area of photoelectrochemistry at the Hahn-Meitner-Institute, Berlin. He spent one year as a DuPont Guest Scientist in Wilmington, Deleware, before he got his Habilitation in Physical Chemistry at the Free University of Berlin. He was appointed as the Head of the Department of Interfaces at the Hahn-Meitner-Institute. In 1997, he became a Full Professor with the Chair of Surface Science in the newly founded Department of Materials Science, TU Darmstadt. His main research fields are: Surface Science, Photovoltaic Converters, Intercalation Batteries, Inorganic/Organic Composites, Semiconductor Interfaces, Photoelectrochemistry. Since 2006, Prof. Dr. Jaegermann also serves as the Dean of the Department.