Effect of Third Component on Efficiency and Stability in Ternary Organic Solar Cells: More than a Simple Superposition

Ternary organic solar cells (OSCs) have attracted much attention due to them being high‐performance solar cells. Ternary OSCs represent an efficient strategy to gain both the benefits of enhanced photon energy harvesting using multiple organic materials, similar to that in tandem OSCs, and the easy fabrication of simple single‐junction device structures. The properties of ternary OSCs are closely related to their complex energy/charge dynamics mechanisms and unique thermodynamic features of blend morphology and crystallinity. Hence, there is much more to introducing a third component into a binary blend than the simple superposition of individual components. Herein, the role of the third component is mainly discussed to provide in‐depth insights into ternary OSCs. This review categorizes and describes the effects that the role and function of the third component have on the efficiency and stability of ternary OSCs. Finally, in addition to a summary on the current research progress, outlooks for future research directions are also addressed.