Comparison of charge accumulation and transport in nanostructured dye-sensitized solar cells with electrolyte or CuSCN as hole conductor

The charge transport properties of the dye-sensitized solar cells consisting of Ru(dcbpyH2)2(NCS)2-sensitized nanostructured TiO2 with either redox electrolyte or CuSCN as hole conductor have been compared. The electron transport time and the electron charge in the TiO2 varies in a similar way with the incident light intensity for both hole conductors: electron transport becomes faster and electron accumulation increases with increasing light intensity. Electron transport in the CuSCN-based cells is significantly faster than in electrolyte cells under conditions where the accumulated charge is equal. An ultra-thin aluminum oxide layer on the nanocrystalline titanium oxide has a beneficial effect as it reduces the recombination and increases the open-circuit potential.