Efficiency of Exciton and Charge Carrier Photogeneration in a Semiconducting Polymer
Schins, Juleon M.
Candeias, L. P.
Siebbeles, L. D. A.
University of Exeter (at the time of publication Euan Hendry was affiliated to Leiden University); Leiden University; Delft University of Technology; FOM Institute for Atomic and Molecular Physics, Amsterdam
Physical Review Letters
American Physical Society
We determine the efficiencies for the formation of excitons and charge carriers following ultrafast photoexcitation of a semiconducting polymer (MEH-PPV). The simultaneous, quantitative determination of exciton and charge photoyields is achieved through subpicosecond studies of both the real and the imaginary components of the complex conductivity over a wide frequency range. Predominantly excitons, with near-unity quantum efficiency, are generated on excitation, while only a very small fraction (<10-2) of free charges are initially excited, consistent with rapid (∼100 fs) hot exciton dissociation. These initial charges are very short lived, decaying on subpicosecond time scales.
Euan Hendry, Juleon M. Schins, L. P. Candeias, L. D. A. Siebbeles, and Mischa Bonn, Physical Review Letters, Vol. 92, article 196601 (2004). "Copyright © 2004 by the American Physical Society."
92 (19), article 196601