Electromodulation of charge-transfer photoexcitations in pristine and C{sub 60}-doped conjugated polymers

Journal Article · Thu Apr 01 04:00:00 EST 1999 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.59.11053· OSTI ID:336693

Liess, M; Vardeny, Z V ^[1]; Lane, P A ^[2]

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1. Department of Physics, University of Utah, Salt Lake City, Utah 84112 (United States)
2. Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH (United Kingdom)

We study the effect of an electric field of up to 100 kV/cm on photoexcitations in pristine and C{sub 60}-doped {pi}-conjugated polymers by electromodulated photoinduced absorption (EPA). In EPA, we measure changes in the photoinduced absorption of a polymer film induced by an electric field. The dominant effect is a change in the photoexcitation recombination kinetics, which leads to reduction or enhancement of the PA bands. We found that the electric field increases the decay rate of charge-transfer excitations; exciton dissociation near defects and impurities was also enhanced. A Stark shift of the photoexcitation energy levels for C{sub 60}-doped poly({ital para}-phenylene) was also detected. From the EPA we calculate that the polarizability of the charge-transfer excitations in this blend is of order 3{times}10{sup 7}({Angstrom}thinsp){sup 3}. This is two orders of magnitude larger than the polarizability of the 1B{sub u} exciton in most luminescent conjugated polymers. {copyright} {ital 1999} {ital The American Physical Society}

• OSTI ID: 336693
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 16 Vol. 59; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTRA
CHARGE TRANSPORT
DEFECTS
DOPED MATERIALS
ELECTRO-OPTICAL EFFECTS
EXCITATION
EXCITONS
FULLERENES
MODULATION
POLYMERS
RECOMBINATION
STARK EFFECT
THIN FILMS