Flexible, metal-free composite counter electrodes for efficient fiber-shaped dye-sensitized solar cells

Highly flexible metal-free fibrous electrodes are prepared using commercial carbon fiber (CF) and poly(3,4-ethylene dioxythiophene)-polystyrene sulfonate (PEDOT:PSS) aqueous solution. Multiple highly ordered CF monofilaments act as the conductive cores, while the PEDOT:PSS films act as the catalytic shell in the composite fibrous electrode. Cyclic voltammetry and electrochemical impedance spectroscopy are carried out to systematically investigate the electrochemical performance, and the results indicate that the composite fibrous electrode is highly efficient in catalyzing I3-/I-. PEDOT:PSS conductive films also show excellent compatibility with CF and resistance to solvent. The low-cost composite electrodes are used as counter electrodes to fabricate fiber-shaped dye-sensitized solar cells, and the highest conversion efficiency of 5.5% is achieved, which is comparable to the performance of platinized CF counter electrode-based device. (C) 2012 Elsevier B.V. All rights reserved.