Effects of gold nanoparticles inlaid in the photo-electrode on the properties of dye-sensitized solar cells

Abstract

In this study, we prepared gold nanoparticles by electrochemical synthesis and inlaid in the photo-electrode of dye-sensitized solar cells (DSSCs) to study the surface plasma resonant (SPR) and light-scattering effects on the properties of dye-sensitized solar cells. The analyses of field emission scanning electron microscopy (FE-SEM) show that the average diameter of gold nanoparticles is 50nm. The results of ultraviolet–visible absorption spectra show that the absorption wavelength is about 533nm for gold nanoparticles. The conversion efficiency with different amounts of gold nanoparticles in TiO2 photo-electrodes is 5.42%, 5.92%, 6.06%, and 5.51% with the amounts of 0μL, 300μL, 400μL, and 500μL, respectively. The best conversion efficiency of the dye-sensitized solar cells with gold nanoparticles added is 6.06%, and is higher than that the cells without gold nanoparticles, which is 5.42%. In addition, in order to study light-scattering effects on the photo-electrode, different thicknesses of large particle size TiO2 (~250nm) coated onto photo-electrode to form double layer structure. The best conversion efficiency of the dye-sensitized solar cells with gold nanoparticles added and with the thickness of 3.3μm light scattering layer is 7.10%, which is higher than that of the cell without light-scattering layer, which is 6.06%. This result indicates that the effect of gold nanoparticles on the photo-electrode can increase the conductivity and reduce the recombination of charges in the photo-electrode, and the light-scattering structure can enhance light transmission path in TiO2 films and the absorption of photons in the photo-electrode, resulting in the increase of the photoelectric conversion efficiency for DSSCs.