Advancements in morphology controllable ternary organic solar cells for active layers

The performance of ternary organic solar cells is highly dependent on the microscopic morphology of their active layers. This review summarizes recent advances in the field of morphology control, focusing on the influence of donor and acceptor material selection, the role of additives, solvent optimization, the strategic use of a third component, and annealing treatments. This review also discusses the film-forming mechanisms of active layers and explores the effects of active layer thickness on device performance. The fine-tuning of the center core, end groups, and side chains of donor/acceptor materials, the uniform dispersion of additives, the use of suitable solvents to form fiber structures, and the strategic selection of a third component can be effectively used to optimize the crystallinity, intermolecular aggregation, phase separation size, and phase purity of active layers, thereby improving morphology and enhancing device performance. The review also outlines key future research directions in active layer modulation. This work provides a survey of recent advances in morphology controllable ternary organic solar cells, which is crucial for the advancement of sustainable photovoltaic technologies and promotes the transition to renewable energy sources. • The film-forming mechanism of the active layer of ternary organic solar cells is summarized. • The strategy of active layer morphology regulation for ternary organic solar cells is reviewed. • The regulation scheme of active layer thickness of ternary organic solar cells is presented.