CuInS₂ Nanocrystals/PEDOT:PSS Composite Counter Electrode for Dye-Sensitized Solar Cells

An inorganic/organic nanocomposite comprised of CuInS(2) nanocrystals and poly(styrenesulfonate)-doped poly(3,4-ethylenedioxythiophene) (CIS/PEDOT:PSS) was explored as a promising candidate for the counter electrode (CE) in dye-sensitized solar cells (DSCs). Cyclic voltammetry measurements confirmed that this composite electrode exhibited better catalytic activity compared with pristine CuInS₂ or PEDOT:PSS electrode. Electrochemical impedance spectroscopy revealed that the composite film constitutes a three-dimensional catalytic network. The DSC using this composite CE can yield 6.50% photoelectric conversion efficiency, which is comparable to that of the conventional platinum CE (6.51%) and better than that of the pristine CuInS₂ (5.45%) or PEDOT:PSS (3.22%) electrode.