Exciton Dissociation Dynamics in Quasibilayer Organic Solar Cells: Mechanisms, Regulation Strategies, and Prospects

Exciton dissociation dominates charge generation and power conversion efficiency in organic solar cells (OSCs). Conventional bulk heterojunction OSCs are plagued by uncontrollable morphology, serious charge recombination, and insufficient exciton utilization. Layer‐by‐layer deposition enables the construction of quasibilayer OSCs with well‐defined vertical phase separation and ordered charge‐transport channels, which offers a promising route to overcome the above bottlenecks. This review first systematically elaborates the general fundamental mechanisms of exciton dissociation in OSCs, covering basic processes, charge–transfer states, and singlet–triplet interconversion dynamics, and then focuses on the regulation strategies for exciton dissociation in OSCs from four aspects: morphology engineering, energy‐level alignment, electric‐field/polarization effects, and spin‐state regulation. Next, the synergistic effect of structural features and energy‐level engineering on exciton dissociation in quasibilayer OSCs is highlighted to address current challenges in optimizing this process. Finally, future research directions for quasibilayer OSCs are proposed, including thick‐film compatibility and scalable processing. This review provides a comprehensive understanding of exciton dissociation in quasibilayer OSCs and offers guidance for developing high‐efficiency, stable, and industrializable OSCs.