Organic or plastic photovoltaics offer the potential for ubiquitous low cost solar energy harvesting. The efficiency of these devices, however, depends in detail on the nanometer scale structure of the active material. Polymer photovoltaics generally consist of a semiconducting polymer, which serves as the photoabsorber and the excited state electron donor, and a fullerene derivative, which serves as the electron acceptor. To create the most efficient devices, polymers and fullerenes must be blended on the nanometer lengthscale to ensure efficient charge separation; the components must also be partly separated to create ideal conductive pathways for the photogenerated carriers to reach the electrodes. Creating this optimized network is one of the major challenge in the production of high efficiency photovoltaics. In this talk, we explore new ways to control architecture in organic photovoltaic materials, focusing on the use of solution phase self-assembly. We specifically design amphiphilic semiconducting polymers and fullerenes that can co-assemble in aqueous solutions. In these assemblies, we can use simple geometric constraints to predict how molecules will assemble, and we use that knowledge to create electron transfer cascades that can pull charge carriers apart. These biomimetic assemblies are able to keep electrons and holes separated for unprecedented periods of time – days or even weeks. Future translation of these self-assembly ideas to organic PV devices has the potential to dramatically improve efficiency in low cost PV.

Control of nanoscale architecture in organic photovoltaic materials: From plastic solar cells to biomimetic assemblies with extremely long-lived carriers

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.