<p>This study investigates the effects of promising electron donors and modified π-bridge structures in organic dyes on the photoelectronic properties and charge transfer dynamics of solar cells. Using density functional theory (DFT) and time-dependent DFT (TD-DFT), the geometric, electronic structures and optical properties were systematically investigated via a two-step design strategy: initial optimization by π-bridge modification, followed by further refinement through precise electron-donor regulation. Additionally, quantum dynamics simulations were employed to clarify how these two strategies influence charge transfer at the dye/TiO₂ interface. The calculation results indicate that, compared with <b>B1</b> dye, the addition of a planar-conjugated thiophene to modify the π-bridge effectively broadens the spectral absorption range and enhances the donor-acceptor coupling and charge injection at the dye/TiO₂ interface. The non-planar propeller-shaped 4,4’-dimethoxytriphenylamine groups (<b>D1</b>), endowed with excellent electron-donating properties, exhibit superior light-harvesting capability and synergistically enhance the electron transport performance of the dye through conjugation effects with the thiophene π-bridge. Overall, these findings significantly deepen our understanding of the effects of structural modifications in organic dyes and provide valuable insights for designing efficient dye sensitizers.</p>