Recent progress in ternary organic solar cells based on solution-processed non-fullerene acceptors

The ternary blending strategy of introducing a third component into binary organic solar cells (BOSCs) is a feasible and efficient strategy to optimize the performance of BOSCs. Ternary organic solar cells (TOSCs) have an adjustable absorption band for matching the solar light characteristics, easily adjustable photoelectric performance and tunable micro-morphology; therefore, they have become a hotspot in the field of OSC research. Currently, the power conversion efficiency (PCE) of TOSCs has been boosted over 17%. Herein, we give a review on the four possible working mechanisms of TOSCs, roles of the third component in TOSCs, recent progress made in different kinds of active layer materials of TOSCs based on solution-processed non-fullerene acceptors (NFAs), and recent advances in large-area TOSCs and their long-term stability. This review can provide some guidance for the further development of TOSCs. Finally, to help researchers understand the future of TOSCs, the challenges and prospects of TOSCs based on solution-processible NFAs have been provided.