Optimization of polymer electrolytes for quasi-solid-state 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:I2 =3:3:3:7:1 (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.