Controlling the ordering of polymer systems has been the Holy Grail within the polymer community over the past 60 years. Researchers have used additives and processing variability to control the final properties of these commodity based polymer systems. One of the next generation, macromolecular materials - semiconducting polymers – presents new challenges since the functional properties (i.e. conductivity) of such systems are dependent on their molecular ordering. Furthermore, many functional polymer based devices (e.g. polymer solar cells) require complex, multicomponent and multi-layered systems. Thus, control of the micro-structure within these systems is of utmost importance for the successful development of the next generation polymer-based devices, which will be important, e.g., for the European Photovoltaic industry to remain competitive in a market which experiences a strong and increasing competition from companies in China, Taiwan or Korea. This proposal aims to use nucleating agents – dditives commonly utilized to manipulate the soldification of semicrystalline polyolefins – to control the ordering within conducting polymers and their corresponding blends. We will use this information to establish relevant structure-property interrelationships in these functional macromolecular structures, advance reliable processing protocols, and design the next generation of nucleating agents specifically for combination with conductive polymer materials.