Time-resolved terahertz spectroscopy is used for investigation of photoinduced charge carrier dynamics in blends of a polyfluorene copolymer (poly[2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4‘,7‘-di-2-thienyl -2‘,1‘,3-benzo-thiadiazole)]) and an electron acceptor ([6,6]-phenyl-C61-butyric acid methyl ester). The transient far-infrared response appears instantaneously after photoexcitation. We show that the transient conductivity spectrum is dominated by two major contributions: response of separated charge carriers and response of coupled polaron pairs.

J. Phys. Chem. C

Nemec, H., Nienhuys, H.-K., Zhang, F., Inganäs, O., Yartsev, A., & Sundström, V. (2008). Charge carrier dynamics in alternating polyfluorene copolymer : fullerene blends probed by terahertz spectroscopy. J. Phys. Chem. C, 112, 6558–6563. doi:10.1021/jp710184r