Perylene‐diimide‐based cathode interlayer materials for high performance organic solar cells

Abstract Organic solar cells (OSCs), benefiting from their significant advantages, such as light weight, flexibility, low cost, and large area manufacturing adaptability, are considered promising clean energy technologies. Currently, the power conversion efficiency (PCE) of state‐of‐the‐art OSCs has reached over 18% through materials and device engineering. Specifically, cathode engineering with cathode interlayer materials (CIMs) is an important strategy to improve the PCEs and stability of OSCs. Among various CIMs reported in the literature, perylene diimides (PDIs) are more appropriate for working as cathode interlayers in OSCs owing to their distinct advantages of suitable energy levels, high electron affinity, high electron mobility, and facile modification. In this review, the mechanism of cathode engineering is concisely summarized, and recent research progress on PDI derivatives working as CIMs in OSCs is systematically reviewed. Finally, prospects and suggestions are provided for the development of PDI‐based CIMs for practical applications.