The effect of the third component on high performance ternary organic solar cells: A review

Abstract In recent years, with the continuous development of photoactive layer material, the power conversion efficiency (PCE) of bulk heterojunction (BHJ) binary organic solar cells (BOSCs) has been significantly improved. However, it is difficult for BOSCs to maximize the effective utilization of the wide spectrum of solar energy, limiting the further improvement of PCE. Adding a third component to BOSCs that constructing ternary organic solar cells (TOSCs) is an effective method to broaden the absorption spectrum of BOSC, match the gradient energy level, and regulate the morphology of the active layer. Constructing TOSCs can not only effectively improve the device performance, but also maintain the advantages of easy‐to‐fabricate single‐junction device structures. In this review, we first introduced the basic working mechanism of TOSCs. Then based on the working mechanism, we comprehensively reviewed the latest research results of TOSCs, and analyzed the effects of the third component on the microscopic morphology of the active layer, photovoltaic performance and device stability. Finally, we systematically summarized the role of the third component in TOSCs and proposed some future development trends of TOSCs, such as designing and synthesizing more economical, green, and environmentally friendly TOSCs that towards the commercial application in the future.