The A–D–A′–D–A-type non-fused ring electron acceptors(NFREAs),consisting of electron-donating unit(D)as the bridge to link electron-accepting units(A and A′),have emerged as promising electron acceptors for organic solar cells(OSCs)and organic photodetectors(OPDs).As the units are linked by the carbon–carbon single bonds,these electron acceptors generally possess feasible synthesis and tunable optoelectronic properties.Herein,the recent progress of A–D–A′–D–A-type NFREAs is reviewed,including molecular design,device performance,structure–property relationships,and their applications in OSCs and OPDs.Finally,we discuss the challenges and propose the perspectives for the further development of A–D–A′–D–A-type NFREAs.
