Organic Redox Couples and Organic Counter Electrode for Efficient Organic Dye-Sensitized Solar Cells

Org. thiolate/disulfide redox couples were synthesized and were studied systematically in dye-sensitized solar cells (DSCs) from an org. dye (TH305). Photophys., photoelectrochem., and photovoltaic measurements were performed to get insights into the effects of different redox couples on the performance of DSCs. The polymeric, org. poly(3,4-ethylenedioxythiophene) (PEDOT) material also was introduced as counter electrode in this kind of noniodine-contg. DSCs showing a promising conversion efficiency of 6.0% under AM 1.5 G, 100 mW cm-2 light illumination. Detailed studies using electrochem. impedance spectroscopy and linear-sweep voltammetry reveal that the redn. of disulfide species is more efficient on the PEDOT counter electrode surface than on the commonly used platinized conducting glass electrode. Both pure and solvated ionic-liq. electrolytes based on a thiolate anion were studied in the DSCs. The pure and solvated ionic-liq.-based electrolytes contg. an org. redox couple render efficiencies of 3.4% and 1.2% under 10 mW cm-2 light illumination, resp.