(609c) Solar Cells Based On Sensitized Nanowire Arrays

Solar cells can provide an abundant, clean, and sustainable source of electricity, but high costs have limited their implementation.  The use of sensitized nanostructured architectures may enable both low-cost processing and high efficiency by decoupling the functions of light harvesting and charge transport into different materials.  Sensitized solar cells consist of a bicontinuous interpenetrating network of electron- and hole-transporting materials with an interfacial absorber layer.  In this architecture, interfacial recombination is the dominant loss process, so controlling the interfacial chemistry during deposition is critical.  I will present our group’s work on the use of ZnO nanowire arrays sensitized by thin CdSe coatings to produce extremely thin absorber (ETA) solar cells.  Nanowire arrays can provide direct pathways for electron transport as well as sufficient surface area for sensitization.  Progress in sensitized nanowire-based solar cells will be presented, as well as some of the challenges for improving their efficiencies.  Overcoming these challenges will require detailed fundamental understanding and control of charge transfer in the materials and interfaces within the cells.