Abstract
Using femtosecond time-resolved photoinduced absorption spectroscopy, we have studied the dynamics of photoinduced electron transfer from semiconducting polymers to . We find that with in poly[2-methoxy-5-(2’-ethyl-hexyloxy)-p-phenylene vinylene)], poly(2,5-bis(cholestanoxy)-1,4-phenylene vinylene), and poly(3-octylthiophene) (P3OT), ultrafast photoinduced electron transfer occurs from the band of the semiconducting polymer to the lowest unoccupied molecular-orbital level of . Time-resolved measurements of the dichroic ratio place a 300-fs upper limit on the electron transfer time. The charge-separated state is rendered metastable due to the spatial separation of the electron and hole and to polaron formation associated with the electron on the and the hole on the semiconducting polymer. Increasing the concentration in P3OT increases the lifetime of the charge-separated state. The two p-phenylene vinylene derivatives also displayed metastable charge separation.
- Received 13 July 1994
DOI:https://doi.org/10.1103/PhysRevB.50.18543
©1994 American Physical Society