February 24, 2010
FRONTIERS IN MATERIALS SCIENCE
VINSE COLLOQUIUM SERIES
Dr. David Ginger
Department of Chemistry; University of Washington
"Nanostructured Solar Cells: From Light Harvesting with Nanoparticles to Organic Film Morphology"
ABSTRACT. Organic solar cells are a potential low-cost alternative to conventional inorganic photovoltaics. The most successful organic solar cells to date rely on nanoscale phase separation between different components as the basis for their operation. Understanding and controlling this nanoscale film structure is a central challenge that affects every aspect of the field, from the optimization of new low-bandgap polymers to early efforts to scale up manufacturing. Our group has pioneered several scanning-probe methods, including time-resolved electrostatic force microscopy (trEFM) and photoconductive atomic force microscopy (pcAFM), as tools to characterize the influence of nanoscale film morphology in active organic solar cells. These data show the power of scanning-probe methods in correlating morphology with performance, and underscore the need to model these devices as fully 3D heterogeneous networks, rather than as homogeneous 1D or 2D semiconductor slabs. Finally, we discuss the spectral properties of plasmonic near-field excitation enhancements near colloidal nanoparticles, which might find use in applications with extremely thin light absorbing layers.