Photorefractive conjugated polymer-liquid crystal composites

Michael R Wasielewski, B. A. Yoon, M. Fuller, G. P. Wiederrecht, M. P. Niemczyk, W. A. Svec

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

A new mechanism for space-charge field formation in photorefractive liquid crystal composites containing poly(2,5-bis(2′-ethylhexyloxy)-1,4-phenylenevinylene) (BEH-PPV) and the electron acceptor N,N′-dioctyl-1,4:5,8-naphthalenediimide, NI, is observed. Using asymmetric energy transfer (beam coupling) measurements that are diagnostic for the photorefractive effect, the direction of beam coupling as a function of grating fringe spacing inverts at a spacing of 5.5 μm. We show that the inversion is due to a change in the dominant mechanism for space-charge field formation. At small fringe spacings, the space-charge field is formed by ion diffusion in which the photogenerated anion is the more mobile species. At larger fringe spacings, the polarity of the space charge field inverts due to dominance of a charge transport mechanism in which photogenerated holes are the most mobile species due to hole migration along the BEH-PPV chains coupled with interchain hole hopping. Control experiments are presented, which use composites that can access only one of the two charge transport mechanisms. The results show that charge migration over long distances leading to enhanced photorefractive effects can be obtained using conjugated polymers dissolved in liquid crystals.

Original languageEnglish
Title of host publicationMaterials Research Society Symposium - Proceedings
PublisherMaterials Research Society
Pages211-219
Number of pages9
Volume597
Publication statusPublished - 2000
EventThin Films for Optical Waveguide Devices and Materials for Optical Limiting - Boston, MA, USA
Duration: Nov 30 1999Dec 3 1999

Other

OtherThin Films for Optical Waveguide Devices and Materials for Optical Limiting
CityBoston, MA, USA
Period11/30/9912/3/99

Fingerprint

Conjugated polymers
Electric space charge
Liquid crystals
Liquid Crystals
Composite materials
Charge transfer
Energy transfer
Anions
Negative ions
Ions
liquid crystal polymer
Electrons
Experiments

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

Cite this

Wasielewski, M. R., Yoon, B. A., Fuller, M., Wiederrecht, G. P., Niemczyk, M. P., & Svec, W. A. (2000). Photorefractive conjugated polymer-liquid crystal composites. In Materials Research Society Symposium - Proceedings (Vol. 597, pp. 211-219). Materials Research Society.

Photorefractive conjugated polymer-liquid crystal composites. / Wasielewski, Michael R; Yoon, B. A.; Fuller, M.; Wiederrecht, G. P.; Niemczyk, M. P.; Svec, W. A.

Materials Research Society Symposium - Proceedings. Vol. 597 Materials Research Society, 2000. p. 211-219.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Wasielewski, MR, Yoon, BA, Fuller, M, Wiederrecht, GP, Niemczyk, MP & Svec, WA 2000, Photorefractive conjugated polymer-liquid crystal composites. in Materials Research Society Symposium - Proceedings. vol. 597, Materials Research Society, pp. 211-219, Thin Films for Optical Waveguide Devices and Materials for Optical Limiting, Boston, MA, USA, 11/30/99.
Wasielewski MR, Yoon BA, Fuller M, Wiederrecht GP, Niemczyk MP, Svec WA. Photorefractive conjugated polymer-liquid crystal composites. In Materials Research Society Symposium - Proceedings. Vol. 597. Materials Research Society. 2000. p. 211-219
Wasielewski, Michael R ; Yoon, B. A. ; Fuller, M. ; Wiederrecht, G. P. ; Niemczyk, M. P. ; Svec, W. A. / Photorefractive conjugated polymer-liquid crystal composites. Materials Research Society Symposium - Proceedings. Vol. 597 Materials Research Society, 2000. pp. 211-219
@inproceedings{30ca9544e4384277b59456b94aa1f881,
title = "Photorefractive conjugated polymer-liquid crystal composites",
abstract = "A new mechanism for space-charge field formation in photorefractive liquid crystal composites containing poly(2,5-bis(2′-ethylhexyloxy)-1,4-phenylenevinylene) (BEH-PPV) and the electron acceptor N,N′-dioctyl-1,4:5,8-naphthalenediimide, NI, is observed. Using asymmetric energy transfer (beam coupling) measurements that are diagnostic for the photorefractive effect, the direction of beam coupling as a function of grating fringe spacing inverts at a spacing of 5.5 μm. We show that the inversion is due to a change in the dominant mechanism for space-charge field formation. At small fringe spacings, the space-charge field is formed by ion diffusion in which the photogenerated anion is the more mobile species. At larger fringe spacings, the polarity of the space charge field inverts due to dominance of a charge transport mechanism in which photogenerated holes are the most mobile species due to hole migration along the BEH-PPV chains coupled with interchain hole hopping. Control experiments are presented, which use composites that can access only one of the two charge transport mechanisms. The results show that charge migration over long distances leading to enhanced photorefractive effects can be obtained using conjugated polymers dissolved in liquid crystals.",
author = "Wasielewski, {Michael R} and Yoon, {B. A.} and M. Fuller and Wiederrecht, {G. P.} and Niemczyk, {M. P.} and Svec, {W. A.}",
year = "2000",
language = "English",
volume = "597",
pages = "211--219",
booktitle = "Materials Research Society Symposium - Proceedings",
publisher = "Materials Research Society",

}

TY - GEN

T1 - Photorefractive conjugated polymer-liquid crystal composites

AU - Wasielewski, Michael R

AU - Yoon, B. A.

AU - Fuller, M.

AU - Wiederrecht, G. P.

AU - Niemczyk, M. P.

AU - Svec, W. A.

PY - 2000

Y1 - 2000

N2 - A new mechanism for space-charge field formation in photorefractive liquid crystal composites containing poly(2,5-bis(2′-ethylhexyloxy)-1,4-phenylenevinylene) (BEH-PPV) and the electron acceptor N,N′-dioctyl-1,4:5,8-naphthalenediimide, NI, is observed. Using asymmetric energy transfer (beam coupling) measurements that are diagnostic for the photorefractive effect, the direction of beam coupling as a function of grating fringe spacing inverts at a spacing of 5.5 μm. We show that the inversion is due to a change in the dominant mechanism for space-charge field formation. At small fringe spacings, the space-charge field is formed by ion diffusion in which the photogenerated anion is the more mobile species. At larger fringe spacings, the polarity of the space charge field inverts due to dominance of a charge transport mechanism in which photogenerated holes are the most mobile species due to hole migration along the BEH-PPV chains coupled with interchain hole hopping. Control experiments are presented, which use composites that can access only one of the two charge transport mechanisms. The results show that charge migration over long distances leading to enhanced photorefractive effects can be obtained using conjugated polymers dissolved in liquid crystals.

AB - A new mechanism for space-charge field formation in photorefractive liquid crystal composites containing poly(2,5-bis(2′-ethylhexyloxy)-1,4-phenylenevinylene) (BEH-PPV) and the electron acceptor N,N′-dioctyl-1,4:5,8-naphthalenediimide, NI, is observed. Using asymmetric energy transfer (beam coupling) measurements that are diagnostic for the photorefractive effect, the direction of beam coupling as a function of grating fringe spacing inverts at a spacing of 5.5 μm. We show that the inversion is due to a change in the dominant mechanism for space-charge field formation. At small fringe spacings, the space-charge field is formed by ion diffusion in which the photogenerated anion is the more mobile species. At larger fringe spacings, the polarity of the space charge field inverts due to dominance of a charge transport mechanism in which photogenerated holes are the most mobile species due to hole migration along the BEH-PPV chains coupled with interchain hole hopping. Control experiments are presented, which use composites that can access only one of the two charge transport mechanisms. The results show that charge migration over long distances leading to enhanced photorefractive effects can be obtained using conjugated polymers dissolved in liquid crystals.

UR - http://www.scopus.com/inward/record.url?scp=0034540336&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034540336&partnerID=8YFLogxK

M3 - Conference contribution

VL - 597

SP - 211

EP - 219

BT - Materials Research Society Symposium - Proceedings

PB - Materials Research Society

ER -