Free-standing polypyrrole films as substrate-free and Pt-free counter electrodes for quasi-solid dye-sensitized solar cells

Substrate-free and Pt-free counter electrodes (CE) were utilized for dye sensitized solar cells for the first time using free-standing polypyrrole (PPy) films. The PPy films were synthesized by liquid-liquid biphasic interfacial polymerization. These films have unique morphologies as they have a dense base (that provides mechanical strength) and porous top (resulting in large surface area for catalytic activity). The electrochemical impedance spectroscopy measurements revealed that free-standing PPy exhibit reasonable catalytic activity for I-3(-)/I- redox couple. The dye-sensitized solar cells were fabricated using N3 dye, gel polymer electrolyte and free-standing PPy films as CE. The power conversion efficiency measured under AM 1.5, 100 mW/cm(2) illumination was similar to 3.5%. (C) 2012 Elsevier B.V. All rights reserved.