Photorefractivity in liquid crystals doped with a soluble conjugated polymer

Gary P. Wiederrecht, Walter A. Svec, Mark P. Niemczyk, Michael R Wasielewski

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

1 Citation (Scopus)

Abstract

Photoconductive polymers are doped into liquid crystals to create a new mechanism for space-charge field formation in photorefractive liquid crystal composites. The composites contain poly(2,5-bis(2′-ethylhexyloxy)-1,4-phenylenevinylene) (BEH-PPV) and the electron acceptor N,N′-dioctyl-1,4:5,8-naphthalenediimide, NI. 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 publicationProceedings of SPIE - The International Society for Optical Engineering
PublisherSociety of Photo-Optical Instrumentation Engineers
Pages13-20
Number of pages8
Volume3800
Publication statusPublished - 1999
EventProceedings of the 1999 Liquid Crystals III - Denver, CO, USA
Duration: Jul 21 1999Jul 22 1999

Other

OtherProceedings of the 1999 Liquid Crystals III
CityDenver, CO, USA
Period7/21/997/22/99

Fingerprint

photorefractivity
Conjugated polymers
Electric space charge
Liquid crystals
space charge
liquid crystals
spacing
polymers
composite materials
Charge transfer
Composite materials
doped crystals
Energy transfer
polarity
Negative ions
energy transfer
gratings
inversions
anions
Electrons

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Wiederrecht, G. P., Svec, W. A., Niemczyk, M. P., & Wasielewski, M. R. (1999). Photorefractivity in liquid crystals doped with a soluble conjugated polymer. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 3800, pp. 13-20). Society of Photo-Optical Instrumentation Engineers.

Photorefractivity in liquid crystals doped with a soluble conjugated polymer. / Wiederrecht, Gary P.; Svec, Walter A.; Niemczyk, Mark P.; Wasielewski, Michael R.

Proceedings of SPIE - The International Society for Optical Engineering. Vol. 3800 Society of Photo-Optical Instrumentation Engineers, 1999. p. 13-20.

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

Wiederrecht, GP, Svec, WA, Niemczyk, MP & Wasielewski, MR 1999, Photorefractivity in liquid crystals doped with a soluble conjugated polymer. in Proceedings of SPIE - The International Society for Optical Engineering. vol. 3800, Society of Photo-Optical Instrumentation Engineers, pp. 13-20, Proceedings of the 1999 Liquid Crystals III, Denver, CO, USA, 7/21/99.
Wiederrecht GP, Svec WA, Niemczyk MP, Wasielewski MR. Photorefractivity in liquid crystals doped with a soluble conjugated polymer. In Proceedings of SPIE - The International Society for Optical Engineering. Vol. 3800. Society of Photo-Optical Instrumentation Engineers. 1999. p. 13-20
Wiederrecht, Gary P. ; Svec, Walter A. ; Niemczyk, Mark P. ; Wasielewski, Michael R. / Photorefractivity in liquid crystals doped with a soluble conjugated polymer. Proceedings of SPIE - The International Society for Optical Engineering. Vol. 3800 Society of Photo-Optical Instrumentation Engineers, 1999. pp. 13-20
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