Ultrafast dynamics of photoexcited states in C [sub 60]

摘要: We have measured the relaxation of photoexcited states in C[sub 60] using femtosecond excitation at energies corresponding to the h[sub 1u][yields]t[sub 1u] bandgap. Induced absorption with a fast 2ps relaxation is observed, which has bimolecular kinetics indicative of exciton-exciton annihilation. The induced absorption is spectrally broad with peaks at 1.92 and 2.25 eV. These features are assigned to excited-state absorption from the t[sub 1u] level to higher-lying h[sub g] excited states at [proportional to]4.0 eV. (orig.).