Precursor states for charge carrier generation in conjugated polymers probed by ultrafast spectroscopy.
Phys Rev Lett
; 88(14): 147401, 2002 Apr 08.
Article
en En
| MEDLINE
| ID: mdl-11955173
ABSTRACT
Photocurrent experiments using two femtosecond laser pulses are performed on a photodiode using a ladder-type conjugated polymer as the active layer. With a photon energy of 3.1 eV the first pulse excites singlet excitons. A time-delayed second pulse with a photon energy of 2.49 eV leads to a decrease of the photocurrent by exciton depletion due to stimulated emission. S1 excitons being dissociated during their entire lifetime are identified as the only relevant channel for charge carrier generation. Intrachain polaron pairs are also formed on an ultrafast time scale with a yield of approximately 10%. They can be efficiently dissociated by reexcitation with photons of an energy of 1.9 eV.
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01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Phys Rev Lett
Año:
2002
Tipo del documento:
Article
País de afiliación:
Alemania