Using THz time domain spectroscopy, we investigate ultrafast photoconductivity in two conjugated polymers, derivatives of poly(phenylene vinylene) (MEH-PPV) and polythiophene (RR-P3HT), to investigate free charge carrier dynamics. We find that the ultrafast photo-conductivity due to free charges is larger in the RR-P3HT than in the MEH-PPV sample. These charges are long-lived, remaining mobile for several nanoseconds, in contrast to the picosecond decay of free charges in MEH-PPV. By comparing our measured conductivities to charge mobilities inferred from microwave absorption measurements, we make estimates for the free carrier quantum yields.
Chem. Phys. Lett.

Hendry, E, Koeberg, M, Schins, J.M, Siebbeles, L.D.A, & Bonn, M. (2006). Free carrier photogeneration in polythiophene versus poly(phenylene vinylene) studied with THz spectroscopy. Chem. Phys. Lett., 432, 441–445. doi:10.1016/j.cplett.2006.10.105