An inexpensive and efficient pyridine-based additive for the electrolyte of dye-sensitized solar cells

We report on the synthesis and application of an inexpensive pyridine-based additive allyl isonicotinate (AIN) for the efficient dye-sensitized solar cells (DSCs). AIN can be quickly synthesized at room temperature without any solvent. The presence of AIN in the electrolyte enhances the open-circuit voltage (V_oc), fill factor (FF) and short-circuit photocurrent (J_sc), consequently improving the energy conversion efficiency (η) from 6.5% to 8.2%. The impedance experiments show that the adsorption of AIN leads to the negative shift of the conduction band edge of the dye-sensitized TiO₂ around 55 mV. The presence of AIN in the electrolyte can obviously suppress the recombination of the injected electrons, increasing the lifetime of electrons in the TiO₂. The negative shift of the conduction band edge and the suppression of the recombination of the injected electrons contribute to the higher power conversion efficiency.