Water-soluble multiwall-carbon-nanotube-polythiophene composite for bilayer photovoltaics

A water-soluble acid oxidized multiwall carbon nanotube (o-MWCNTs)-polythiophene composite for bilayer photovoltaics is reported. Discrete heterojunction photovoltaic cells utilizing this nanocomposite material as the donor layer exhibit a similar to 20% increase in fill factor and commensurate increase in power conversion efficiency as compared to cells without o-MWCNTs. Crucially o-MWCNTs are incorporated into the cell structure using an environmentally compatible solvent without complicating the process of device fabrication. (c) 2006 American Institute of Physics.