Application of Bis-PCBM in Polymer Solar Cells with Improved Voltage

In recent years, fullerene bis-adducts have gained significant interest within the academic community due to their high-lying LUMO level. Herein, we carried out device optimization of the photovoltaic performances of novel photovoltaic polymer PBDTBDD with Bis-PCBM, and several characterization techniques including photoluminescence quench analysis, X-ray diffraction patterns, and atomic force microscopy were employed. As the synergistic result of balanced mobility, better crystallinity, efficient exciton dissociation, and charge transport efficiency, high fill factor and short-circuit current density as well as power conversion efficiency were achieved in the PBDTBDD/Bis-PCBM device. In addition, the optimized PSC device based on PBDTBDD:Bis-PCBM (1:1, wt/wt) with 3 vol % DIO yielded a high PCE of 6.07% with Voc of 1.00 V, Jsc of 10.02 mA/cm2, and FF of 60.54% under the illumination of AM1.5G, 100 mW/cm2. Therefore, we reported that polymer/Bis-PCBM-based polymer solar cells obtain both high efficiency ∼6% and high Voc ≈ 1 V, which exhibited PBDTBDD/Bis-PCBM and is a promising blue absorber unit for tandem devices, and also paved a path to optimization of other polymer/Bis-PCBM systems.