Enhancing the Performance of Dye-Sensitized Solar Cells with a Three-Layer Photoanode

Dye-sensitized solar cells (DSCs) have garnered significant attention due to their high power conversion efficiency and low production cost-effectiveness. In this study, we developed a hierarchically structured three-layer TiO₂ photoanode via hydrothermal synthesis to significantly enhance DSC performance. The optimized device achieved a short-circuit current density of 16.92 mA/cm² and a photoelectric conversion efficiency of 8.34%, representing improvements of 15.67% and 20.5%, respectively, compared to traditional DSCs with a single-layer TiO₂ photoanode in our study. The significance lies in the rational design principle rather than absolute efficiency. This performance enhancement stems from the complementary functions of each architectural layer: (1) a bottom layer of TiO₂ nanocrystals providing high surface area for dye adsorption, (2) an intermediate layer of vertically aligned TiO₂ nanorods enabling efficient electron transport, and (3) a top layer of TiO₂ microspheres simultaneously boosting dye loading and light harvesting through enhanced light scattering. Our findings demonstrate that rational design of multi-layered photoanode architectures can effectively address the competing demands of surface area, charge transport, and light management in high-performance DSCs.