Synthesis and characterization of novel chalcogen based materials for applications in organic electronics

Abstract

In times of climate change renewable energy sources have gained great importance and conversion of solar radiation into electricity using photovoltaic panels enables environment friendly and sustainable power supply. The use of semiconductive organic polymers is an attractive alternative to their inorganic counterparts, which enables the fabrication of lexible, lightweight devices while lowering production costs. In the course of this work novel materials based on sulfur containing building blocks were developed for applications in organic photovoltaics. Regarding device architecture they can be converted from an electron donor to an electron acceptor by oxidation using dimethyldioxirane (DMDO) and thus, give rise to the new concept of continuous junction (CJ). Several new building blocks exhibiting dialkyne and dialdehyde functionalities have been synthesized to facilitate different polymerization techniques such as Glaser coupling, McMurry coupling and Knoevenagel polycondensation. The obtained materials have been characterized by transmission as well as cyclic voltammetry measurements. Cooperation with the Freiburg Materials Research Center enabled us to incorporate the synthesized polymers into test devices and record their corresponding current voltage characteristics. Oxidation experiments during device manufacturing were carried out but unfortunately did not lead to the desired results. Therefore optimization regarding polymer design and fabrication techniques remains subject to future investigations.