BHJ OSCs based on PTB7–Th andSCPDT–

BHJ OSCs based on PTB7–Th andSCPDT–PDI4 exhibited favorable phase separations and highelectron mobilities with a PCE up to 7.11%. Aiming to suppressthe over-aggregation of PDI units and improve the phase separation and morphology of BHJ film, we also developed PDI-basedacceptors through incorporating fluorine atoms [128]. OSCs thatemployed PTB7–Th as the donor and FPDI–CDTph2F (Fig. 9) asthe acceptor exhibited a PCE up to 6.03% without any posttreatment. Derived from SCPDT–PDI4, we synthesized FSPthrough directly fusing PDI units with SCPDT-core [129]. FSPexhibited extended p-conjugation and optimized molecular configuration which leads to better photon absorption and moredesirable energy levels. OSCs based on PTB7–Th/FSP achievedPCE up to 8.89% with the photovoltaic properties better thanSCPDT–PDI4-based devices (Table 2).