Reid et al, J. Phys. Chem. C 2010 , 114 , 20672-20677

1. Imaging Damage in Plastic Solar Cell Materials on the NanoscaleDavid S. Ginger, University of Washington, DMR 1005504 Plastic solar cells that are solution-processable have the potential to be a low-cost, large-scale technology but need to have improved efficiencies and lifetimes. Charge traps decreases both efficiency and lifetime. Because the nanostructure of these plastic solar cells varies with processing conditions, we investigated two scanning probe techniques to image areas we intentionally damaged by forming charge traps. Our results verified that charge traps resulted from light exposure and that device performance decreased with increasing light-induced damage. We successfully mapped the effect of localized damage by measuring the charging rate at specific points on the solar cell. With this imaging, we detected damage even at the lowest photon doses which still decrease device efficiency. This charging rate imaging technique will allow us to investigate mechanisms limiting efficiency and performance on the nanoscale. A laser coaligned with a sharp probe is used to create photooxidized, intentionally-damaged spots in a plastic solar cell made from a nanostructuredpolyfluorene blend. After the spots have been created, we map the damaged areas as shown above using time-resolved electrostatic force microscopy to measure local charging rates. Areas with more light exposure are more damaged and show decreased charging rates. The change in charging rate correlates to the change in device efficiency, with faster charging rates corresponding to better device performance. Reid et al, J. Phys. Chem. C 2010,114, 20672-20677

2. Plastic Solar Cells at WorkDavid S. Ginger, University of Washington, DMR 1005504 • Under the theme “Plastic Solar Cells in Work”, the Ginger Lab held an educational display together with the Hillhouse Lab and Luscombe Lab (both from University of Washington) at the Shoreline “SolarFest” Renewable Energy and Sustainable Living fair – hundreds of people stopped by our booth and learned about solar energy and their applications • REU student Sarah Griesse-Nascimento from Boston University came to learn our time-resolved EFM technique and attenuated total reflectance Fourier transform infrared spectroscopy to characterize photo degradation of plastic solar cells (top and bottom left) PhD Students Kristina Knesting, GlennisRayerman, GuozhengShao and REU student Sarah Griesse-Nascimento explain solar energy to visitors to their booth at the Renewable Energy and Sustainable Living Fair (bottom right) REU student Sarah Griesse-Nascimento poses in front of a glovebox in which her samples for characterization were made