Nanostructured organic solar cells

Existing single-crystal silicon (c-Si) solar cells require sophisticated high-temperature processing, high-quality silicon, and complex engineering, and therefore are not cost-effective as an energy source for most applications (Sun and Sariciftci 2005). In addition, these cells have no or very limited mechanical flexibility. Organic polymer solar cells and dye-sensitized solar cells have become a low-cost alternative to silicon solar cells because they can be fabricated using solution-based processing such as inexpensive painting (K. Kim et al. 2007; Reyes-Reyes et al. 2005a). Other advantages of these cells are their significant flexibility and their ability to be directly fabricated onto most surfaces, including plastics. The most efficient of these devices use a polymer or dye as an electron donor and a second material as the electron acceptor. This chapter describes the application of bulk nanostructured materials to two closely related devices: organic polymer solar cells and dye-sensitized solar cells. The focus is on the successful device structures, important material electronic properties, and nanoscale morphology.