SINGLET AND TRIPLET EXCITED-STATE BEHAVIORS OF C-60 IN NONREACTIVE AND REACTIVE POLYMER-FILMS

The excited state behavior of C-60 has been investigated in polystyrene (PS) and poly(9-vinylcarbazole) (PVCz) polymer films. Picosecond and nanosecond laser flash photolysis techniques are employed to probe the transient absorption properties of singlet and triplet excited states in nonreactive (PS) and reactive (PVCz) microenvironments. In PS film, the absorption properties and lifetimes of these excited states are very similar to those observed in solutions. Encapsulation of C-60 With PS results in the suppression of excited state self-quenching processes. Excited state charge transfer complex formation dominates in PVCz film. The absence of long-lived electron transfer products indicates that the charge separation in PVCz film is short-lived.