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- Grishina, A. D., et al.
(författare)
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Fast photorefractive polymer composites based on nanocrystalline J-aggregates of the
- 2004
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Ingår i: Synthetic Metals. - : Elsevier BV. - 0379-6779. ; 144:2, s. 113-120
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Tidskriftsartikel (refereegranskat)abstract
- The hole and electron drift mobility, photoelectric properties as well as influence of temperature, dark current and also relative position of oxidation potentials of the interacting components on photorefractive characteristics of the composites from aromatic polyimide doped with nanocrystalline J-aggregates of a cyanine dye are presented. The nanocrystalline J-aggregates were used as the photosensitizers and also as nonlinear optical chromophores. The experimental electric field dependence of the charge carrier photogeneration efficiency is well fitted by Onsager equation when the quantum yield of the bound thermalized electron-hole pairs φ0=1 and the initial separation of the charges in the pair r0=14.1Å. The charge photogeneration time constant determines the response time of the photorefractive grating formation. The polymer composites exhibit gain coefficient Γ=218cm-1 and response time shorter than 20ms at applied electric field 50V/μm and a intensity of each writing beam 30mW/cm2. The net gain coefficient Γ-α=143cm -1.
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- Vannikov, Anatoly, et al.
(författare)
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Photorefractive polymer composites for the IR region based on carbon nanotubes
- 2005
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Ingår i: Optics and Spectroscopy (English translation of Optika i Spektroskopiya). - : Pleiades Publishing Ltd. - 1562-6911 .- 0030-400X. ; 99:4, s. pp.643-648
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Tidskriftsartikel (refereegranskat)abstract
- The photorefractive properties of polymer composites based on aromatic polyimide and single-wall carbon nanotubes are studied using radiation at a wavelength of 1064 nm. It is found that the nanotubes possess photoelectric sensitivity in this spectral region and that the kinetic photorefractive characteristics of the polymer composites are entirely determined by the photogeneration and charge transport characteristics of the layers. The two-beam gain coefficient of the signal beam measured for a composite consisting of aromatic polyimide and 0.25 wt % of single-wall carbon nanotubes in a constant electric field E 0 = 79 V/μm is equal to 84 cm -1 and exceeds the optical absorption coefficient by 59 cm -1 . The refractive index modulation is equal to Δn = 0.004 at E 0 = 54 V/μm. © 2005 Pleiades Publishing, Inc.
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