Facile syntheses of N-alkylaziridino[60]fullerenes and their application in polymer solar cells

N-alkylaziridino[60]fullerenes (NAAFs) were synthesized through the reaction of C60 and primary alkylamines with the aid of di(acetoxyiodo)benzene (DIB) and I2 under mild conditions. The NAAFs exhibit similar LUMO energy levels (−3.82 eV to −3.89 eV), which is comparable with PC61BM. The NAAFs are thermally stable with the decomposition temperature over 230 °C and show good solubility in common organic solvents. Polymer solar cells based on N-phenylethylaziridino[60]fullerene/P3HT (0.5:1, w/w) demonstrated a good power conversion efficiency of 2.92% under the illumination of 86 mW/cm2. The solar cells kept good performance (PCE = 2.71%) even with a very low fullerene content (N-phenylethylaziridino[60]fullerene/P3HT = 0.3:1, w/w).