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Electric Field Induced Ionization of the Exciton in Poly(Phenylene Vinylene)

Published online by Cambridge University Press:  21 March 2011

Jian Wang ,
Daniel Moses ,
Alan J. Heeger ,
N. Kirova  and
S. Brazovski
Jian Wang
Affiliation:
Institute for Polymers and Organic Solids, University of California, Santa Barbara, CA 93103, U.S.A.
Daniel Moses
Affiliation:
Institute for Polymers and Organic Solids, University of California, Santa Barbara, CA 93103, U.S.A.
Alan J. Heeger
Affiliation:
Institute for Polymers and Organic Solids, University of California, Santa Barbara, CA 93103, U.S.A.
N. Kirova
Affiliation:
LPTMS, Bat.100, Universite Paris-Sud, 91405, Orsay-Cedex, France
S. Brazovski
Affiliation:
LPTMS, Bat.100, Universite Paris-Sud, 91405, Orsay-Cedex, France
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Abstract

The exciton binding energy (Eb) and the band gap energy (Eg) of poly(phenylene vinylene), PPV, have been determined by photoconductivity excitation profile spectroscopy as a function of light polarization, applied electric field, and temperature. The spectral signature of the exciton is a narrow peak (100 meV full width at half maximum) that emerges just below the band edge upon increasing the external field, the temperature or the defect density. The exciton peak is observed only for light polarized parallel to the chain axis. The exciton binding energy is obtained from the energy of the exciton peak with respect to the band edge and, independently from analysis of the field dependence of the exciton dissociation. It is Eb ≈ 60 meV.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 660: Symposia JJ – Organic Electronic & Photonic Materials and Devices , 2000 , JJ2.10
Copyright
Copyright © Materials Research Society 2001

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References

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