Fabrication of highly efficient flexible dye-sensitized solar cells

Abstract

The paper studies the fabrication of a flexible dye-sensitized solar cell (DSSC). The photoelectrode substrates are flexible stainless steel sheet with thickness 0.07 mm and titanium (Ti) sheet with thickness 0.25 mm. For the photoelectrode fabrication process, eletrophoresis deposition (EPD) was employed for its merits of low-cost and fast fabrication. With an electric field of 40 V/cm, after undergoing EPD process twice, the TiO 2 nanofilm thickness could be controlled to around 13 μm thick. In addition, to achieve counter electrode, sputtering method was applied to deposit Pt on ITO-PET, resulting in thin films with four different thicknesses of 5, 8, 11 and 14 nm. The experimental results showed that the best colloid solution used in EPD process was a mixture of 100 ml isopropyl alcohol (IPA) and 0.4 g commercial TiO 2 nanoparticles, Degussa P25. The best flatness for a 13 μm thick film could be acquired under an electric field of 40 V/cm. Comparing the photoelectric conversion efficiency values of DSSC assembled by counter electrodes with different Pt thicknesses, the experimental results showed that the best Pt thickness was 11 nm, and the conversion efficiency could reach as high as 2.91%.