Synthesis and Photovoltaic Properties of Novel Monoadducts and Bisadducts Based on Amide Methanofullerene

Four new [6,6]-phenyl-C-61 and C-71 butylsaure n-dibutyl amides (PCBDBA) with mono- and bis-adduction on C-60 and C-70 cages, respectively, have been synthesized as models to study the effect of the mono- and bis-adduction on fullerene cages on device performance when used as electron acceptors with the donor of regioregular P3HT in bulkheterojunction organic photovoltaics (BHJ-OPV). The optoelectronic, electrochemistry, and photovoltaic properties of these mono- and bis-products were fully investigated. The best device performance of these fullerene derivatives were obtained from the two monoadducts with power conversion efficiency (PCE) of 1.77% for C-60 derivative and 1.90% for C-70 derivative, respectively, which are close to PCBM's 2.43%. The results revealed the structure function relationship among the mono adduct and bisadduct derivatives of C-60 and C-70 with the BHJ-OPV performance.