Efficient electrolyte of N,N′-bis(salicylidene)ethylenediamine zinc(ii) iodide in dye-sensitized solar cells

N,N′-Bis(salicylidene)ethylenediamine zinc(II) iodide (ZnLI2) was synthesized and characterized by elemental analysis, UV-Vis and IR spectroscopies. This new Schiff base complex was, for the first time, applied as the electrolyte of a dye-sensitized solar cell. ZnLI2 has high reductive activity and conductivity, resulting in larger IPCE and photoelectric conversion efficiency in the DSSCs. The best results were obtained in the optimized composite electrolyte E2, with a photoelectric conversion efficiency of 7.75% under 100 mW cm−2 irradiation. This work provides a new approach for the improvement of the photoelectrochemical properties of dye-sensitized solar cells.