The Synthesis of Asymmetric Perylene Diimide Acceptors and Their Optoelectronic Properties Studies

Inspired by the advantages of heteroatoms introducing and molecular structure symmetry-breaking in construction of non-fullerene acceptors (NFAs), in this contribution, we designed and synthesized three asymmetric perylene diimide (PDI) based acceptors by annulating a selenophene and/or fusing a thiophene ring at the bay position. Using commercially purchased PBDB T as electron donor, a best power conversion efficiency (PCE) of 5.32% was achieved for selenophene-annulated PDI (PDI2 Se), while higher PCE of 6.10% was obtained for the thiophene fused one (PDI2 FT). Interestingly, PDI2Se FT, in which the S and Se atoms introduced simultaneously, showed the best photovoltaic performance among the three asymmetric NFAs with an optimal PCE of 6.96%. This result demonstrates that incorporation of diverse heteroatoms at the bay positions to construct asymmetric configuration is a robust design strategy for high performance PDI-based NFAs.