High-efficiency ternary nonfullerene polymer solar cells with increased phase purity and reduced nonradiative energy loss

In this work, we used a ternary blend strategy to improve the photovoltaic performance of organic solar cells (OSCs). PBDB-T:IDT-EDOT-based binary blend devices show a power conversion efficiency (PCE) of 9.93%, and the ternary devices with PC 71 BM as the third component exhibit a PCE of 12.07% with simultaneously enhanced V oc , J sc and FF. The broadened absorption, optimized morphology and balanced charge carrier mobility of these devices are responsible for these improvements. The introduction of PC 71 BM can disperse the IDT-EDOT aggregates, enhance the phase purity, and increase the electroluminescence quantum efficiency (EQE EL ). Furthermore, the performance of the ternary devices is not very sensitive to the weight ratio of the two acceptors. PCEs of over 11% are obtained even though the composition gradually varies from 1:1:0.2 to 1:0.4:0.8. Our results demonstrate that PC 71 BM is a highly promising second acceptor for the construction of high-efficiency ternary OSCs. The ternary blend device demonstrates a significantly improved PCE of 12.07% with increased phase purity and reduced nonradiative energy loss.