Highly Efficient Benzo-Furan-Based Electron Acceptor Derived from One-Pot Synthesis for High-Performance Bulk Heterojunction Solar Cells

A new benzofuran-derived fulleropyrrolidine derivative denoted as FB-C60 is synthesized by Prato single step synthetic protocol and successfully utilized as an electron acceptor in the bulk heterojunction organic solar cells (OSCs). The molecule possesses significant optoelectronic and redox properties, which are compatible with popular polymer donors. The OSCs constructed from PTB7/FB-C60 blends yielded a highest power conversion efficiency (PCE) of 8.1%. The champion device that was fabricated from PTB7-Th/FB-C60 bulk-composite film demonstrated a PCE of 9.6%, open circuit voltage of 0.83 V, series resistance of 3.3 Ω·cm–2 and 75.1% of external quantum efficiency at 640 nm wavelength. A promising electron mobility of 1.2 × 10–3 cm2 V–1 s–1 of FB-C60 is observed in the fabricated device. FB-C60 shows the potential to positively replace the conventional PCBM to fabricate “cost-effective” high-performance OSCs.