Hexagonal Cu2-xS nano-crystals thin films as a high catalytic counter electrode for dye solar cells with ferrocene-based liquid electrolytes

In this work, the application of hexagonal CuS nanoparticle layers as counter electrodes for dye sensitized solar cells has been studied. A fast, cheap and reliable deposition method was proposed for the one-step preparation of Cu2−xS layers on F-doped SnO2 within 30 min through an ink-based technique. The electrodes prepared with our method were tested with iodine/iodide electrolyte, Co(II)/(III) bipyridine redox shuttle and Fe(II)/(III) ferrocene-based liquid electrolyte. The Cu2−xS layers showed high efficiency and stability with the ferrocene/ferrocenium redox couple, showing a fast charge recombination kinetic, low charge transfer resistance (Rct=0.73 Ω cm2), reasonably high limiting current (11.8 mA cm−2) and high stability in propylene carbonate