Influence of various cations on redox behavior of I- and I3- and comparison between KI complex with 18-crown-6 and 1,2-dimethyl-3-propylimidazolium iodide in dye-sensitized solar cells

In this paper, we studied the influence of different cations on redox behavior of I- and I3- by cyclic voltammetry and electrochemical impedance spectroscopy. It was demonstrated that increasing cation size tends to give rise to higher reductive activity of I- and lower diffusion coefficient of I3- in these cations, alkylimidazolium, [Na 15-C-5]+ and [K 18-C-6]+. Moreover, we measured the performance of dyesensitized solar cells (DSCs) with electrolyte containing [K 18-C-6]I or 1,2-dimethyl-3-propylimidazolium iodide (DMPII). It was found that dye-sensitized solar cells (DSCs) with [K 18-C-6]I give a little higher short-circuit photocurrent density and a little lower fill factor than DSCs with DMPII.