Functional group addition of [6,6]-phenyl-C61-butyric acid methyl ester as electron acceptor in polymer solar cells with high performance

Abstract The 3,4-bis(bromomethyl) methoxybenzene addition product of [6,6]-phenyl-C 61 -butyric acid methyl ester (PCBM), namely, 2-methoxy-(5,8)-dihydronaphthyl-PCBM (MDN-PCBM), was designed, synthesized, and evaluated for its photovoltaic performance in polymer solar cells (PSCs). The energy level of the lowest unoccupied molecular orbital of MDN-PCBM is −3.79 eV, which is higher than that of PCBM. The PSCs based on poly(3-hexylthiophene) with MDN-PCBM exhibit a significantly higher power conversion efficiency (3.67% versus 3.09%), open circuit voltage (0.58 V versus 0.54 V), and short-circuit current (8.80 mA/cm 2 versus 8.40 mA/cm 2 ) than the device with PCBM as the electron acceptor under an illumination of AM 1.5 G at 82 mW/cm 2 . Results indicate that MDN-PCBM is a more promising new acceptor than PCBM for high-performance PSCs.