Observation of fluorescence emission from solutions of C60 and C70 fullerenes and measurement of their excited-state lifetimes

Singlets lead to photogeneration inC60-based organic heterojunctions

“…Furthermore, the photoluminescence is shown to originate from the singlet state by measurements of its PL spectrum and fluorescent lifetime. To our knowledge, this is the first transient measurement of the C 60 lifetime in thin films at room temperature, and it allows for a comparision with the previously reported singlet lifetime of C 60 in a dilute solution [20].…”

“…Transient PL further shows that singlet emission from the C 60 thin film has a lifetime of 590 ± 10ps. This is shorter than the reported singlet lifetime of C 60 in solvent of 1.17ns [20]. Note that our photoexcitation falls within the range of ~2.1eV to ~3.2eV, whereby either the Frenkel or charge transfer (CT) states are excited [25][26][27].…”

Zero-field optical detected magnetic resonance of [70]-fullerene

“…Because of the extremely low phosphorescence quantum yield of 3C 60 [3,4] and the fact that the TI-S o transition is -in contrast to [70]-fullerene -additionally orbital-forbidden, the investigation of [60]-fullerene has turned out to be quite complicated. In contrast, fluorescence and phosphorescence of [70]-fullerene can be detected quite easily using standard techniques.…”

Self‐Crystallization of C70 Cubes and Remarkable Enhancement of Photoluminescence

“…The main component can be assigned to the S 1 -S 0 transition of a C 70 molecule, as its time constant is close to the lifetime of the S 1 state of an individual C 70 molecule in solution. [38,39] That is, interactions between C 70 molecules in the cube crystal may be negligible, so that fluorescence quenching, which is observed frequently in molecular aggregates, does not occur. On the other hand, the TRPL of C 70 powder shows much faster decay, which is consistent with the much weaker fluorescence intensity of the powder.…”