Dynamic Characteristics of Aggregation Effects of Organic Dyes in Dye-Sensitized Solar Cells

摘要: Two organic dyes (LS-1 and IQ4) containing identical electron donor acceptor units but distinct π result in significantly different power conversion efficiency of the corresponding dye-sensitized solar cells (DSSCs): LS-1, 4.4%, IQ4, 9.2%. Herein, we combine first-principle calculations molecular dynamics to explore aggregation effects LS-1 IQ4 by comparing their optical properties intermolecular electronic couplings. The calculated absorption spectra are good agreement with experimental observations reveal them be evidently affected dimerization. Furthermore, simulations show that steric hindrance induced diphenylquinoxaline unit can elongate distances between or donors, which responsible for fact coupling is about 10 times larger than IQ4. More importantly, aggregated remains almost perpendicular TiO2 surface, whereas gradually tilts during dynamic simulation, impacting injection recombination several ways, clarifies why leads photocurrent higher efficiency. deep understanding dye sheds new light on complex factors determining DSSC function paves way rational design high-efficiency self-anti-aggregation sensitizers.