TRANSIENT ABSORPTION, LIFETIME AND RELAXATION OF C60 IN THE TRIPLET-STATE

Transient absorption and time-resolved thermal lensing techniques have been used to study the photophysical behavior of C60 in benzene solution at room temperature. After the photoexcitation with a 308 nm XeCl excimer laser, the triplet state was the only transient species detectable with the 10 ns time-resolution. The triplet-triplet absorption spectrum with apparent band peaks at 330 and 745 nm covers the whole spectral range of 290-850 nm. The triplet lifetime in air-free benzene is 49 +/- 1-mu-s and essentially all the photon energy absorbed is released as heat, predominantly through the triplet state.