Single-wall carbon nanotube/conjugated polymer photovoltaic devices

We report the optoelectronic properties occurring in single-walled carbon nanotubes (SWNTs)—conjugated polymer, poly(3-octylthiophene) composites. Composite films were drop or spin cast from a solution on indium–tin oxide (ITO) and quartz substrates and studied using absorption spectroscopy and electrical characterization methods. Diodes (Al/polymer-nanotube composite/ITO) with a low nanotube concentration (<1%) show photovoltaic behavior, with an open circuit voltage of 0.7–0.9 V. The short circuit current is increased by two orders of magnitude compared with the pristine polymer diodes and the fill factor also increases from 0.3 to 0.4 for the nanotube/polymer cells. It is proposed that the main…