Photoinduced Absorption in P3HT/PCBM Bulk Heterostructures
We investigate the dynamics of charged states (polarons) in bulk heterostructures of polythiophene and fullerene derivatives by means of photoinduced absorption spectroscopy, and is compared them with those in pristine polythiophene thin films. Polaron lifetimes in the bulk heterostructure and in polythiophene thin films at 6 K exceed 140 and 17 μs, respectively. The difference in lifetime indicates that charged states are better stabilized by the addition of the fullerene derivative. We also find that the dynamics of intrachain singlet excitons, which are not observed in the bulk heterostructure, are different from that of polarons in polythiophene thin films.
Hyungsun Kim, JianFeng Yang, Tohru Sekino, Masakazu Anpo and Soo Wohn Lee
K. Kinoshita et al., "Photoinduced Absorption in P3HT/PCBM Bulk Heterostructures", Materials Science Forum, Vol. 658, pp. 503-506, 2010