The Impact of Metal Ion Doping on the Performance of Flexible Poly(3,4-ethylenedioxythiophene) (PEDOT) Cathode in Dye-Sensitized Solar Cells

Abstract

Poly(3,4-ethylenedioxythiophene) (PEDOT) film is synthesized on flexible indium-doped tin oxide coated polyethylene naphthalate (ITO-PEN) substrate by electrochemical deposition method. The prepared PEDOT is next used as flexible cathode for dye-sensitized solar cells (DSSCs) toward the regeneration of the triiodide redox couple. The electrochemical results indicate the pristine PEDOT cathode owns a low catalytic activity which can be improved by doping PEDOT with transition metal ions M2+ (M2+ = Mn2+, Co2+, Ni2+, and Cu2+). After optimization, the DSSCs using PEDOT-Mn2+, PEDOT-Ni2+, PEDOT-Co2+, and PEDOT-Cu2+ cathodes generate power conversion efficiencies of 5.19, 4.81, 4.36, and 3.78%, much higher than the pristine PEDOT cathode based counterpart (3.26%).