Rene Lopez (University of North Carolina at Chapel Hill)
Dye Sensitized Solar Cells (DSSCs) differ from conventional semiconductor devices in that they separate the function of light absorption from charge carrier transport. At the heart of a DSSC is a metal oxide nanoparticle film, which provides a large effective surface area for adsorption of light harvesting molecules. The films need to be thick enough to absorb a significant fraction of the incident light but increased thickness results in diminished efficiencies due to augmented recombination. Here we introduce a new structural motif for the photoanode in which the traditional random nanoparticle oxide network is replaced by vertically aligned bundles of oxide nanocrystals. The direct pathways provided by the vertical structures appear to provide for enhanced collection efficiency for carriers generated throughout the device. The fabrication method is materials agnostic as similar structures will be shown in Nb2O5, TiO2 and SrTiO3.