Polythiophene-sensitized TiO2 solar cells

Polythiophene-sensitized, nanocrystalline TiO2-based photoelectrochemical cells were fabricated either by using poly (3-thiophene acetic acid) (P3TAA) or a co-polymer; poly(3-thiophene acetic acid)-poly(hexyl thiophene) (P3TAA-PHT) polymers and their performances were examined. The photocells were able to generate reasonably high photocurrent, which increases in the presence of the electron-donating ionic liquids in the electrolyte composed of redox couple I-3(-)/I-. Dramatic enhancements in the cell performances were observed with the addition of ionic liquid 1-methyl-3-n-hexylimidazolium iodide into the electrolyte. While the cell sensitized with P3TAA generated a short-circuit photocurrent of similar to9.75 mA cm(-2), an open-circuit photovoltage of similar to405 mV and a total power conversion efficiency of similar to2.4% under simulated full sunlight of 100 mW cm(-2) (air mass 1.5) the cell sensitized with copolymer P3TAA-PHT delivered similar to1.6% efficiency under the same conditions with similar to7 mA cm(-2) as photocurrent and similar to375 mV as photovoltage. The corresponding incident photon-to-current conversion efficiencies (IPCE) of the above cells were similar to60 and similar to40%, respectively. (C) 2004 Elsevier B.V. All rights reserved.