Heteroatom substitution-induced asymmetric A-D-A type non-fullerene acceptor for efficient organic solar cells

Research on asymmetric A-D-A structured non-fullerene acceptors has lagged far behind the development of symmetric counterpart. In this contribution, by simply replacing one sulfur atom in indacenodithiophene unit with a selenium atom, an asymmetric building block SePT and a corresponding asymmetric non-fullerene acceptor SePT-IN have been developed. Asymmetric SePT-IN achieved a high efficiency of 10.20% in organic solar cells when blended with PBT1-C, much higher than that of symmetric TPT-IN counterpart (8.91%). Our results demonstrated an effective heteroatom substitution strategy to develop asymmetric A-D-A structured non-fullerene acceptors. (C) 2019 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.