The possibility of target control of the electro-optical properties of polymethacrylate with covalently bound azobenzene chromophores in a side chain by introducing metal ions capable of chromophore coordination, acceptor substituents that change the dipole moment of an azobenzene fragment, and organic dyes that expand the range of light absorption of azobenzene chromophore were considered. The mechanism of action of these factors was analyzed.

We investigated the photoconducting and photovoltaic properties of thin film composites derived from poly-N-epoxypropylcarbazole doped with molecules of two organic conductors, namely, tetrathiafulvalene and nickel dithiolene derivatives. These compounds were found to possess hole photoconductivity. The internal photoeffect is a function of the photogeneration of the charge carriers from the additive molecules and charge transport through the donor fragments of the polymer matrix.

Recording media for diffraction gratings formation based on polymer films of polyethylene glycol doped with the photoisomerisable azo-dye Methyl Orange have been developed. Holographic recording of the plane wave front for parallel and orthogonal orientation of polarization vectors of light beams have been performed at room temperature. In order to optimize the recording conditions and obtain high-efficient polarization holographic gratings, in the present work we study the dependence the average molecular weight of polymer matrix and solvent system for thin layers formation on the diffraction efficiency. Five PEG polymers were used as host for azo-dye incorporation −1500, 4000, 6000, 10,000 and 40,000, and two solvent systems, EtOH–H2O and THF-H2O, were examined to investigate film-forming properties. It was concluded, that structure of films as well as diffraction efficiency value and curves character strongly depend on PEG molecular weight.

A study was carried out on the photovoltaic and photoconductive properties of fi lm composites of a styrene copolymer with nonyl methacrylate and polyNepoxypropylcarbazole doped with lanthanide complexes Ln 2 L 6 ·PS (Ln = Nd, Eu, Gd, Yb), HL is the carbacylamidophosphate ligand, CCl 3 C(O)N(H)P(O)(NEt 2 ) 2 , N-[bis(diethylamino) phosphoryl]2,2,2-trichloroacetamide; PS is 3,6-dipyridin-2-yl-1,2,4,5-tetrazine, C 5 H 4 N–C 2 N 4 –C 5 H 4 N). In the visible spectral range, these composites were found to have holetype photoconductivity. The internal photoelectric effect is a function of the photogeneration of charge carriers from the metal complex molecules and the sensitizer. EPR was used to study the kinetics of the formation and relaxation of the photogenerated charge carriers. We conclude that the metal complex molecules in the polymer composite enhance the efficiency of photogeneration of nonequilibrium charge carriers and thereby affect the photovoltaic properties of the composites.

We investigated the photoconducting and photovoltaic properties of thin film composites based on polyN-epoxypropylcarbazole dopped with molecules of two organic conductors, namely, tetrathiаfulvalene and Ni-dithiolene derivatives. It was established that these composites have hole photoconductivity, and the internal photoeffect is determined by the photogeneration of the charge carriers from the added molecules and the charge transport through the donor fragments of the polymeric matrix.

New photosensitive polymeric film composites based on oligo-N-glycidylcarbazole oligomer with azobenzene dyes as additives (azobenzene derivatives with a glycidyl group in their structure) were obtained and investigated. It was shown that the created composites exhibit photovoltaic properties when they are irradiated in the absorption region of the azobenzene dye. The mechanism and the photovoltaic effect in the investigated composites are discussed.

The method of holographic interferometry is based on observation in real-time value of the change of the refractive index of solution during and after its illumination with laser light. This method was used to compare the effects of laser illumination on nanosystems containing polymer (in nonionic and anionic form), Au nanoparticles (AuNPs), and photosensitizer Chlorine e6 (Ce6) at variation of these components. The size distribution of scattering objects in the nanosystems in aqueous solution was determined by dynamic light scattering method. It was shown that under illumination with light the variation of the refractive index is localized mostly near the laser beam transmission region for all nanosystems containing AuNPs. For these systems, thermal diffusion into the non-illuminated volume was practically absent. The presence in the nanosystems Ce6 didn’t change the behavior of nanosystems. However, there was heat propagation after the light absorption to the top area of the cuvette for system containing only polymer and Ce6. This might indicate heating of the solvent.

On the base of a new polyurethane with azobenzene dopants, recording media for polarization holography have been created, and their information properties have been studied when recording holograms of a plane wavefront. It has been found that the recording and relaxation times of holograms are short, and it is defined by the processes of trans-cis-isomerization of azobenzene groups without formation of the surface relief in the polymer film The obtained results are of practical interest in the choice of photosensitive materials for holographic recording media for dynamic holography.

Photoconducting polymeric composites (PPCs) containing nanosized organic or inorganic dopants (dyes and their aggregates, nanoparticles of inorganic semiconductors) are already employed as photoactive media in OLEDs, in photoelectric solar energy converters, in optoelectronic elements, and in electrography and holography. The final application is the subject of this chapter. The basic requirements of holographic recording media (HRM) for the photothermoplastic (PTP) recording technique are considered. Features of the PTP recoding are described and the main demands to HRM are formulated: low electric conductivity, high photoconductivity at the light wavelength of the used laser, good film-forming, and optical and thermoplastic properties. The mechanisms of PPC photoconductivity are studied, including photogeneration, recombination, transport, and capture of nonequilibrium charge carriers. These mechanisms are particular to the organic and inorganic disordered nanomaterials with photosemiconducting properties and differ from the mechanisms in crystal materials due to the absence of long- and short-distance orders in the disordered nanomaterials. Possibilities for the development of new polymeric bases for PPC are discussed to provide a realization of the requirements for HRM. A comparison of the photophysical and information properties of HRM based on cooligomers with linear and radial structure is fulfilled similarly to investigations into the influence of nanoparticle size on the photophysical properties of semiconductor materials. The potentials for the improvement of the information characteristics of HRM is considered with concrete examples. "Wet" development of holograms is not required in the PTP holographic recording technique. Thus, this technique can be used not only in visual holography, but mainly, and more effectively, in holographic interferometry for nondestructive quality control, for detection of the residual stresses in metallic units, and for measurements of refractive index, etc. Concrete examples of HRM and devices for their application are described. This information is not only of scientific interest for widening knowledge about the photo processes in PPC, but is also useful for practical applications of photosemiconducting nanomaterials for quality control of the means of production and products, for prevention breakage, crashes, and catastrophes.

The recording media for polarization holography based on azobenzene polymers are obtained by polymer-analogous transformations of polymethacrylic acid and its copolymers with alkyl methacrylates. Their informational properties were investigated when recording holograms of a plane wavefront. It has been found that the recording and relaxation times of holograms are approximately the same. They are defined mainly by the processes of trans-cis-isomerization of azobenzene groups without formation of surface relief of the polymeric film. The efficiency of the trans-cis-isomerization process decreases, if a heavy substituent is present in the azobenzene chromophore. These results are of practical interest in the choice of photosensitive materials for holographic recording media with optimal information characteristics.

Photovoltaic and photoconductive properties of styrene–nonyl-methacrylate copolymer and poly(N-epoxypropylcarbazole) film composites doped with the tetranuclear metal complex Cu 4 L 4 (OCH 3 ) 4 (L – = N,N′-dibenzyl-N″-trichloroacetyltriamidophosphate) and a sensitizer, i.e., an organic compound with intramolecular charge transfer, were investigated. It was found that these composites had hole-type photoconductivity in the visible spectral range. The internal photoelectric effect was determined by the photogeneration of charge carriers from the metal complex and sensitizer. The kinetics of formation and relaxation of photogenerated charge carriers were studied using ESR. It was concluded that metal-complex molecules in the polymer composite increased the efficiency of photogeneration of nonequilibrium charge carriers and affected the composite photovoltaic properties.

The photoconductive and photovoltaic properties of film composites derived from poly-Nepoxypropylcarbazole and additives of some indole derivative dyes, namely, squaraine, thiosquaraine, and croconaine, were studied. Such composites were found to have hole-type photoconductivity. The internal photoelectric effect is a function of the photogeneration of charge carriers from the dye molecules and transport of the holes along the donor fragments of the polymer matrix. The photovoltaic effect decreases in going from squarate to thiosquarate and croconate. This behavior is attributed to greater internal conversion due to the shift of the absorption region of the dyes in the near-IR spectral range.

The comparative refractive index analysis for two systems, Au sol synthesized into solution of dextran-graft-polyacrylamide (D-g-PAA) starlike copolymer and solution of D-g-PAA under laser illumination, has been carried out. It was established that Au nanoparticles (AuNPs) are 1.5–6 nm in size. The size of individual polymer molecule in solution was equal to 50–60 nm. Au/D-g-PAA nanosystem was successfully used as nanocarrier for photodynamic anticancer therapy. To understand the effect of laser illumination on Au sol, the method of holographic interferometry in real time was proposed and experimentally applied. The method is tested using the equipment kit to determine the refractive index (n) and its change (Δn) of liquid and gaseous media. The necessity of such research is determined by the problems existing in practical medicine. To explain the experimental results, a phenomenological model is proposed which takes into account the features of the molecular structure of starlike dextran-graft-polyacrylamide copolymer with incorporated Au nanoparticles. Since under illumination with light with λ irr = 650 nm the variation of n is observed mainly in the small volume of the cell near the laser beam transmission region, and thermal diffusion into the non-illuminated volume is practically absent, these nanosystems could be effective in target photothermal therapy.

Photoconductive and photovoltaic properties of composite films based on poly-N-epoxypropylcarbazole with added new merocyanine dyes derived from fluorene were investigated. The composites were found to have hole-type photoconductivity although the internal photoeffect was determined by photogeneration of charge carriers from dye molecules and transport of holes along polymer-matrix donor fragments according to jump-type conductivity. It was concluded that the photovoltaic response increased if merocyanine dyes with electronic structures close to that of the ideal polymethine were used.

Based on polymers with the addition of azo dyes as chromophores and azopolymers with the same covalently linked chromophores, recording media for polarization holography are created and their properties are studied when recording holograms of a plane wave front with parallel and perpendicular polarization of recording rays. It is found that the diffraction efficiency and the storage time of holograms are much longer in recording media with films of azo polymers in comparison with polymeric solid solutions of azo dyes. In the latter case, the energy of light is spent only for the trans–cis isomerization of azo dye molecules during exposure of holograms and the polymer chains do not undergo deformation with the formation of a surface relief in the polymer film. Therefore, it is preferable to use recording media based on solid solutions of azo dyes in dynamic polarization holography.

Abstract Based on polymers with the addition of azo dyes as chromophores and azopolymers with the same covalently linked chromophores, recording media for polarization holography are created and their properties are studied when recording holograms of a plane wave front with parallel and perpendicular polarization of recording rays. It is found that the diffraction efficiency and the storage time of holograms are much longer in recording media with films of azo polymers in comparison with polymeric solid solutions of azo dyes. In the latter case, the energy of light is spent only for the trans – cis isomerization of azo dye molecules during exposure of holograms and the polymer chains do not undergo deformation with the formation of a surface relief in the polymer film. Therefore, it is preferable to use recording media based on solid solutions of azo dyes in dynamic polarization holography.

Recording media for polarization holography have been created on the basis of 4-((2-bromo-4-nitrophenyl)diazenyl)phenyl methacrylate copolymers, and the properties during that they manifest during recording of holograms of a plane wavefront have been studied. It has been found that the hologram recording rate at room temperature is the same for the perpendicular and parallel polarization of recording rays and the hologram relaxation rate is higher in the case of perpendicular polarization orientation of recording rays. It has been shown that the diffraction efficiency of holograms does not exhibit a monotonic relation with the film softening temperature.

The photoconductive and photovoltaic properties of fi lm composites based on poly-N-epoxypropylcarbazole doped with a metal complex (a derivative of nickel dithiolene) were studied. It was found that these composites possess hole-type photoconductivity and that the internal photoeffect is determined by photogeneration of charge carriers from the metal complex and by transport of holes through the donor fragments of the polymer matrix.

AbstractRecording media for polarization holography have been created on the basis of 4-((2-bromo-4-nitrophenyl)diazenyl)phenyl methacrylate copolymers, and the properties during that they manifest during recording of holograms of a plane wavefront have been studied. It has been found that the hologram recording rate at room temperature is the same for the perpendicular and parallel polarization of recording rays and the hologram relaxation rate is higher in the case of perpendicular polarization orientation of recording rays. It has been shown that the diffraction efficiency of holograms does not exhibit a monotonic relation with the film softening temperature.

The effect of halogens in carbazolyl-containing oligomers on the information properties of recording media in the photothermoplastic method of recording holograms is studied. An increase of photosensitivity was observed for such media with halogens present in their composition. It was shown by photoactivated electron paramagnetic resonance that the lifetime of the photogenerated charge pairs is increased in the presence of halogens. This is due to the increased probability of photogeneration of charge pairs in the triplet state for the modified oligomers compared with their analogs. It is presumed that modification of the photoconductive polymers with halogens is one way of increasing their photosensitivity and for other practical applications (photovoltaics, molecular electronics).