Center for Functional Nanomaterials Seminar

Photovoltaic (PV) materials and technology are expected to provide a more substantial share of our nation's energy needs in the near future. Development of advanced measurement techniques for characterization of a variety of new PV materials, currently under intense research and development across the national labs, universities and the industry, is extremely crucial for understanding the potentials and the limitations of these materials. In this presentation, I will describe my research and findings in understanding the nanoscale electro-optical response of a model organic bulk heterojunction solar cell using the technique of photoconductive atomic force microscopy (PCAFM). Organic bulk heterojunction solar cells are made up of networks of blended n- and p-type molecules with a nanoscale morphology that is crucial to optimal device performance. A careful examination of these photovoltaic materials using the PCAFM technique under different device architectures, tip contact and the use of metal evaporated nanocontact arrays has allowed us to better understand the role of nanomorphology on charge transport. Additionally, the complete study, combining the examination of the bulk morphology by ultra low angle microtomy and device modeling provides better insight on electronic charge transport and 3D material organization in these systems.