Heather Morgan with Dr. Kenneth Singer and Brent Valle

Bulk Heterostructure Morphology in Polymer Photovoltaics

Recently there has been a rising interest in using organic semiconductors for solar power generation. Compared to inorganic semiconductors, organics are cheaper and easier to process, are lightweight, and can be made into flexible cells. As a result of the physics of organic semiconductors when generating a photocurrent, p and n type materials must be mixed to form a nanoscale network called a bulk heterojunction. The bulk heterojunction diminishes the distance to a p-n junction in the material, which reduces recombination and enhances the efficiency of the cell. The details of the morphology of the bulk heterojunction have a significant impact on the final operation of the solar cell. Therefore, more research into processing techniques and film parameters needs to be performed. I will investigate any correlation between the thickness of the polymer layer or processing conditions and the resulting morphology and, if possible, find a predictable way to direct the growth of these polymers.