Regensburg 2004 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 10: Light Induced Phenomena
CPP 10.1: Vortrag
Montag, 8. März 2004, 15:45–16:00, H 38
Investigations on the dynamics of a photorefractive polymer — •Andre Leopold1, Dietrich Haarer1, Jolita Ostrauskaite2, and Mukundan Thelakkat2 — 1Experimentalphysik IV and BIMF, University of Bayreuth, 95440 Bayreuth, Germany — 2Makromolekulare Chemie I and BIMF, University of Bayreuth, 95440 Bayreuth, Germany
The photorefractive effect is the non-local variation of the refractive index caused by an inhomogenous illumination. This effect is in principle suited for holographic and opto-electronic applications.
At the present time, there is no clear theoretical understanding of the dynamics of the photorefractive effect in polymers. The first model for polymers, developed by Cui et al., was published in 1999. This model and the model for inorganic crystals are applied to a photorefractive guest-host polymer. This material consists of a poly-TPD with a low glass transition temperature, a dicyano dye and the fullerene C60 as sensitizer. The model by Cui et al is sufficient to describe our measurements and gives information on the dominant trap species.
Furthermore, we investigated the influence of the sensitizer concentration on the dynamics and found a significant increase of the grating erasure rate with increasing sensitizer concentration. Additionally, a close correlation of the erasure rates and the conductivities under illumination is observed. This has the potential to ease up the process of evaluating a material’s characteristics.