Humboldt-Universität zu Berlin - Mathematisch-Naturwissen­schaft­liche Fakultät - SFB 951 - HIOS

Interest in the field of organic electronics is largely provoked by the possibility to fine-tune properties of organic semiconductors by varying their chemical structure. Often, compound design is solely guided by chemical intuition, even though material development would benefit from more rigorous structure-property relationships, which link the chemical structure, material morphology and macroscopic properties. To formulate such relationships, an understanding of physical processes occurring on a microscopic level as well as the development of methods capable of scaling these up to macroscopic dimensions are required. The aim of computer simulations is to facilitate this by zooming in on the behavior of electrons and molecules and by bridging micro- and macroscopic worlds. Here, we describe the current status of methods which allow the linking of molecular electronic structure and material morphology to the mesoscopic/microscopic dynamics of charge carriers and excitons. Special attention is paid to the challenges these methods face when aiming at quantitative predictions.

Access to suitable organic building blocks is an important prerequisite to investigate hybrid inorganic-organic systems and realize first and improved optoelectronic and photonic efficient devices. Therefore, the synthesis of -conjugated molecules that serve as organic semiconductors for efficient charge and energy transport as well as light absorption and emission is of great importance as it allows for the tuning of key properties, including redox potentials, absorption and emission characteristics, and structure formation, as well as secondary parameters, such as processing and stability. In this presentation our group’s recent efforts to generate vacuum-processable -conjugated oligomers will be described. On the one hand, the synthesis of a series of ladder-type oligo(p-phenylene)s will be detailed and their optical and redox properties will be discussed in relation to structural rigidity and chain length.[1] On the other hand, the synthesis of non-symmetrical sexiphenyls carrying various substituents at only one of their termini will be described.[2] Both types of compounds have been investigated with regard to their properties in hybrid inorganic-organic systems within the CRC 951 and some results of these collaborative effort will also be presented.

[1]B. Kobin, L. Grubert, S. Blumstengel, F. Henneberger, S. Hecht, J. Mater. Chem. 22, 4383-4390 (2012)
[2]Y. Germeshausen, H. Kulla, B. Kobin, M. Pätzel, S. Hecht, unpublished results