Recent advances in high-performance organic solar cells enabled by acceptor-donor-acceptor-donor-acceptor (A-DA′D-A) type acceptors

Over the past two years, the emergence of acceptor-donor-acceptor-donor-acceptor (A-DA ' D-A) type non-fullerene acceptors (NFAs) has contributed to the rapid development of organic solar cells (OSCs) with power conversion efficiencies (PCEs) exceeding 18%. In this Minireview, we firstly introduce key factors, including light absorption, energy levels, and morphology of the active layer that affect the performance of OSCs. Then, we spotlight the A-DA ' D-A type acceptors for high-efficiency OSCs reported in recent times and summarize the structure-property relationship from selected examples for future molecular design. We also discuss the recent progress in highly efficient ternary OSCs based on A-DA ' D-A type acceptors. Finally, we forecast several research directions for further development of OSCs toward commercialization.