Organic semiconductors are electronically conjugated molecules or polymers. The electronic coupling in organic materials is in solids complex and depends critically on their intermolecular arrangement. Our group has made significant progress in understanding the molecular packing structure of semiconducting polymers and the morphology of organic materials in thin films. These materials are particularly interesting for energy conversion.
Organic Thermoelectrics: We study the thermoelectric effect in organic materials to determine if organic materials can be used effectively to convert heat to electricity. Diffusion of charge carriers in a thermal gradient in a thermoelectric material allows for conversion of thermal to electrical energy (and by reciprocity the converse). Our lab is working to understanding how to control electrical doping in organic semiconductors and the fundamental processes that influence thermopower in organic assemblies.
Organic Photovoltaics: We are working to understand the fundamental processes in charge generation and extraction, to develop novel processing methods, and to understand the degradation of organic photovoltaics (OPVs). Currently, organic photovoltaic devices have efficiencies near 10% in cells, but relatively low efficiencies in modules. Our approach is to develop well-characterized model systems that reveal the underlying electronic processes in OPVs and enable rational study of their behavior.