Efficient light-scattering functionalized TiO2 photoanodes modified with cyanobiphenyl-based benzimidazole for dye-sensitized solar cells with additive-free electrolytes

Light-scattering functionalized cyanobiphenyl-based benzimidazole was synthesized and applied in the surface modification of dyed TiO2 photoanodes for dye-sensitized solar cells (DSSCs). DSSCs based on the ionic liquid and all-solid-state electrolytes were fabricated and characterized, without the addition of additives in the electrolytes. Compared with electrolytes containing the additive N-butylbenzimidazole (NBB), surface modification of dyed TiO2 photoanodes with cyanobiphenyl-based benzimidazole could enhance the values of the open-circuit photovoltage (V-oc), short-circuit photocurrent density (J(sc)) and the overall PCE of the fabricated DSSCs, due to the suppressed charge recombination rate, the conductivity optimization of the electrolytes and enhanced light harvesting capability at the TiO2 photoanode/electrolyte interface. Under the simulated air mass 1.5 solar spectrum illuminations at 100 mW cm(-2), the fabricated devices achieved a cell efficiency of similar to 6.63% and similar to 5.82% for ionic liquid and all-solid-state electrolytes, respectively. These results provide an alternative strategy for high performance DSSCs with additive-free electrolytes.