Indene Addition of [6,6]-Phenyl-C₆₁-butyric Acid Methyl Ester for High-Performance Acceptor in Polymer Solar Cells

Indene addition product of [6,6]-phenyl-C 61 -butyric acid methyl ester (PC 60 BM), indene-PC 60 BM (IPC 60 BM), was synthesized by a one-pot reaction of indene and PC 60 BM at 180 °C for 12 h, for combining the advantages of PC 60 BM and indene-C 60 bis-adduct in the application as acceptor in polymer solar cells (PSCs). The lowest unoccupied molecular orbital (LUMO) energy level of IPC 60 BM is 0.12 eV up-shifted than that of PC 60 BM. The PSC based on poly(3-hexylthiophene) (P3HT) as donor and IPC 60 BM as acceptor shows a higher V oc of 0.72 V and higher power conversion efficiency (PCE) of 4.39% under the illumination of AM1.5G, 100 mW/cm 2, while the PSC based on P3HT/PC 60 BM displays V oc of 0.58 V and PCE of 3.49% only. The results indicate that IPC 60 BM is a better acceptor than PC 60 BM for the P3HT-based PSCs and could be a promising new acceptor instead of PC 60 BM for high-performance PSCs.