Tuning the dye aerosol impaction and TiO2 nanoparticle stacking structures for High-Efficiency Dye-Sensitized solar cells

The rapid manufacturing of high-efficiency dye-sensitized solar cells (DSSCs) is limited by the slow dye adsorption on TiO₂ nanoparticles (NPs)-accumulated photoelectrode using conventional dip-coating process. Therefore, we aim to accelerate the adsorption of dyes that are attached on TiO₂ NPs by employing an aerosol impactor. Herein the aerosolized dyes are designed to get deposited rapidly on the TiO₂ NPs-accumulated photoelectrode. In addition, to effectively trap the irradiated sunlight in DSSCs, we assemble the photoelectrodes incorporated with bilayered TiO₂ thin films comprising small TiO₂ NPs-based underlayer and large TiO₂ NPs-based overlayer as dye-supporting and light-scattering mediums, respectively. Furthermore, the effects of dye aerosol impaction and TiO₂ stacking structures on the efficiency of DSSCs are examined. The power conversion efficiency (PCE) of DSSCs comprising a N719 dye-supporting layer treated with dip-coating process was determined as ～ 5.67%; however, when the bilayered TiO₂ thin films with an optimized thickness ratio of light-scattering overlayer and dye-supporting underlayer were coated with N719 dyes using dye aerosol impactor, the resulting PCE increased to ～ 7.46%. This suggests that the photovoltaic characteristics of DSSCs can be enhanced considerably using the effective TiO₂ NP stacking structures coated with rapid, uniform, and strong aerosol dye adsorption throughout the TiO₂-based photoelectrodes.