An Increase in Energy Conversion Efficiency by Decreasing Cobalt Redox Electrolyte Diffusion Resistance in Dye-sensitized Solar Cells

Cobalt complex redox electrolytes are known to possess high electrolyte diffusion resistances in dye-sensitized solar cells. High resistance was observed not only in the TiO2 pores but also in the bulk of the electrolyte. Therefore, the distance between a dyed TiO2 electrode and a Pt counter electrode was decreased, resulting in increases in the fill factor and short-circuit current. With a carbazole dye, MK-34, an efficiency of 9.3% was obtained under one-sun conditions.