Institut für Angewandte Physik


Organic semiconductors are promising materials for future optoelectronic devices and can be divided into two general classes: small molecules and polymers.

We study the optical properties and the photophysics of these materials, prepared with molecular beam deposition or solution processing techniques, using spectroscopic ellipsometry, temperature dependent NIR-vis-UV spectroscopy, temperature dependent photoluminescence spectroscopy and time-resolved photoluminescence spectroscopy with a time resolution of 200 fs.

The main focus of our research is on blends of small molecules, prepared by coevaporation, and the photophysics of donor-acceptor polymers.

Research objectives

The main focus of our research is on the effects of intermolecular interactions and charge transfer on the optical properties and photophysics of blends of organic semiconductors.

By mixing compounds which differ in their sterical properties and chemical composition we selectively modify the strength of intermolecular interactions and study how this chances the shape of the absorption spectrum (Davydov-splitting), the temperature dependence and shape of the photoluminesence spectrum (emission from charge transfer states) and the lifetime of excited states.

We are interested in two effects: