Hybridsysteme mit einer diskotischen Modellsubstanz

Material hybrid systems consist of materials with different properties what is interesting for electro-optical applications. The aim is to tune specific characteristics of the material in question. In the current work optical, electrical and/or structural investigations have been performed on two different kinds of material composits both based on the utilization of a discotic liquid crystalline model compound. The dispersion of the discotic mesogens into different polymer matrices lead to changes in optical transitions related to intrinsic structural modifications. An energy transfer to laser dye molecules as dopants as well as an energetic shift of the emission maximum due to interactions between mesogen and matrix could be observed. The applicability of the material mixtures as active layer in organic light emitting devices (OLEDs) has been tested. In the second part of this work a novel and very promising hybrid system was structurally and optically characterized. The surface of an inorganic quantum well is covered by a thin film of an organic discotic liquid crystal. The heating of the system to the clearing point of the discotic substance lead to the formation of extraordinary microstructures. The interaction between the organic coating and the inorganic quantum well caused changes in shape and position of the excitonic emission spectrum. There is a strong dependence on the molecular orientation of the discotics. A possible origin for the observed features is the coupling of the dielectric functions of the organic coating and the inorganic quantum well.