Optical limiting performance of dicyanodihydrofullerene

The properties of the excited triplet state of dicyanodihydrofullerene [C60(CN)2] were determined with nanosecond laser photolysis and a picosecond/nanosecond optical limiting (OL) system. It was found that C60(CN)2 possessed a lower quantum yield and higher extinction coefficient of the excited triplet state, which in turn resulted in its similar OL performance for nanosecond laser pulse compared with pristine C60. However, C60(CN)2 shows a better OL performance for picosecond laser pulse, which can be understood according to a three-level model.