Chlorophyll-layer-inserted poly(3-hexyl-thiophene) solar cell having a high light-to-current conversion efficiency up to 1.48%

We report the fabrication of a chlorophyll-layer-inserted poly(3-hexyl-thiophene) (P3HT) solar cell. A significant enhancement in the light-to-current conversion efficiency of up to 1.48% with a fill factor of 0.32 was achieved in a solar cell with a device structure of indium tin oxide anode/poly (3,4-ethylene dioxy-thiophene):poly(styrene sulfonate)/P3HT/chlorophyll/Al cathode under the standard air mass 1.5 irradiation (20 mW/cm(2)). These results suggest that the generation of an internal electric field is mainly due to a difference between the highest occupied molecular orbital of the P3HT (donor) and the lowest unoccupied molecular orbital of the chlorophyll (acceptor), which permits the transfer of photoinduced electrons from P3HT to chlorophyll. (c) 2005 American Institute of Physics.