Charge Separation, Transport and Recombination in Organic Photovoltaics
Organic semiconductor materials are attracting intense interest for photovoltaic (PV) applications because of the prospect of low-cost module production using high throughput processing techniques. For OPV technology to become commercially viable, however, power conversion efficiencies and lifetimes need to be improved relative to their present levels. This will require the development of new materials and improved device or module structures, which in turn requires a thorough understanding of the operation of OPV devices.
In this presentation we will address the fundamental optoelectronic processes involved in current generation in an OPV device, of charge pair generation, charge transport and charge recombination. We will present results for a range of different material systems and address the influence of electronic state disorder, heterogeneity, and the molecular nature of the materials. We will review the experimental techniques and analytical methods that are being developed to study these fundamental processes in organic devices, and outline the main differences with respect to inorganic photovoltaic materials.