Advancements in non-fullerene acceptors for organic solar cells: Brief review of research trends

In the last few decades, fullerene-based acceptors have been extensively utilized in organic solar cells (OSCs). However, OSCs based on fullerenes suffer from low photocurrent and photovoltage due to their poor light absorption capacity and limited tunability of energy levels, which impedes efficiency improvements. Recently, non-fullerene acceptors (NFAs) have enabled rapid progress in OSCs, owing to their favorable properties such as strong light absorption, facile energy level tuning, and improved charge transport characteristics. These features have led to rapid efficiency enhancements. This review discusses the latest research trends related to NFAs, covering several factors that can be applied in the development of NFAs. Finally, we suggest prospects and challenges for high-performance NFA-based OSCs on the path to commercialization.