Optimization of polymer electrolytes for quasi-solidstate dye-sensitized solar cells

The photoelectrochemical properties of the quasi-solid-state dye-sensitized solar cells based on polymer electrolytes consisting of polyethylene oxide (PEO) with the additions of nano-TiO2 and ionic liquid of MPII (1-methyl-3-propylimidazolium iodide) were studied. By using a composite polymer electrolyte of PEO : LiI : TiO2 : MPII : 12 = 3 : 3 : 3 : 7 : I (in mol ratio), the solar energy conversion efficiency of 3.2% under 100 mW-cm(-2) was obtained, which was 8 times higher than that of the cell using polymer electrolyte without any additives. The effect of the additives was attributed to the increase of ionic conductivity of the polymer electrolytes.