Generation of charge carriers in C60 films by 100-fs laser pulses with photon energies above and below the mobility edge

Primary stages of photoinduced processes are studied in C60 films excited b y 100-fs laser pulses at wavelengths of 645 and 367 nm, the fraction of exc ited molecules being no more than several percent. Probing in the broad spe ctral range from 400 to 1100 nm showed that both charged (cations and elect rons) and neutral (excited molecules) components were produced upon irradia tion by the laser pulse. For both excitation wavelengths, charge carriers w ere produced due to direct optical excitation rather than due to singlet-si nglet annihilation. Anions were produced with a delay of 10(-13) - 10(-11) s through electron trapping by C60 molecules.