Carbon nanotube--poly(3-octylthiophene) composite photovoltaic cells

The effects of varying nanotube loading/concentration in carbon nanotube-poly(3-octylthiophene) blends used as thin film photovoltaic cells, have been studied. The network of single walled nanotubes clearly aids in exciton separation and modifies carrier mobility within the active layer as suggested by a bulk heterojunction model. Further, modifications to the metal-polymer interface occur with the addition of nanotubes leading to variations in the observed VOC of the photovoltaic cells. Finally, the "nanocomposite" devices exhibit significant enhancements to external power conversion efficiencies, with the overall efficiency strongly dependent on device design parameters such as the addition of buffer layers.