A strategy of designing near-infrared porphyrin-based non-fullerene acceptors for panchromatic organic solar cells

Two porphyrin-based non-fullerene acceptors (NFAs), PORTIC and PORTFIC, were synthesized to enable panchromatic absorption for high performance organic solar cells (OSCs). An inverted organic solar cell architecture of ITO/ZnO/PTB7-Th:Porphyrin-based NFAs/MoO3/Ag is used. With pyridine as an additive of which further affords optimum morphology for charge separation transport, the power conversion efficiency (PCE) was improved by 40.4% and 67.8% for PORTIC and PORTFIC, respectively, relative to devices fabricated without pyridine. Two-dimensional (2D) grazing-incidence wide-angle X-ray scattering (GIWAXS) shows that the optimized active layer exhibits face-on orientation. Moreover, the photoluminescence quenching experiments reveal that more effective charge transfer between the donor and acceptor is achieved upon addition of pyridine. PTB7-Th:PORTFIC device affords a V-OC of 0.74 V, a J(SC) of 11.27 mA cm(-2), a FF of 51.29% and highest PCE of 4.28%.