An influence of electric field on the transmission of linearly polarized light by the composite films based on polyvinylbutyral doped with the particles of heterometallic complex (NH 4 ) 2 {[Cu(dien)(H 2 O)] 2 [α-V 2 Mo 6 O 26 ]}∙5H 2 O (dien - diethylenetriamine) was studied. Anisotropy of light absorption caused by the electrostatic field was found when of the composites were irradiated with linearly polarized light. The observed electro-optical effect was explained by the appearance of photo-induced optical anisotropy under the influence of linearly polarized light. The anisotropy was changing in space due to the reorientation of the dipole moment of the photogenerated electron-hole pairs in the composite under the action of the external electric field.

Обнаружено, что пленки полимерных композитов на основе поливинилового спирта с добавками ксантенового красителя обладают фотовольтаическими свойствами и фотовольтаический отклик мало изменяется при концентрации красителя более 10 мас. % относительно массы полимера. Фотовольтаический эффект связан с фотогенерацией носителей электрического заряда в агрегатах красителя и транспортом неравновесных носителей заряда между ними. Сделан вывод, что для уменьшения себестоимости фотоактивных сред для фотоэлектрических преобразователей возможно применение дешевых полимеров с малой концентрацией органических красителей.

New photosensitive polymer film composites based on an oligomer containing ferrocenyl and carbazolyl moieties, doped with a merocyanine dye based on ferrocene and tetranitrofluorenone, have been created, and their photoelectric properties have been studied. It has been found that these composites possess photovoltaic properties. The mechanism and features of the photovoltaic effect in the test materials are discussed.

We have obtained and investigated new photosensitive polymeric film composites based on oligo-N-glyci-dylcarbazole oligomer with additives of azobenzene dyes, i.e. azobenzene derivatives with a glycidyl group in their structure. It was shown that the created composites exhibit photovoltaic properties when they are irradiated within the absorption range of the azobenzene dyes. The mechanism and features of the photovoltaic effect in the investigated film composites are discussed.

It has been found that films of polymer composites based on polyvinyl alcohol doped with a xanthene dye possess photovoltaic properties, and the photovoltaic response varies little at the dye concentration greater than 10 wt % with respect to the weight of the polymer. The photovoltaic effect is due to photogeneration of charge carriers in the dye aggregates and transport of nonequilibrium charge carriers among them. It is concluded that, in order to reduce the production cost of photoactive media for photovoltaic cells, it is possible to use cheap polymers with a low concentration of organic dyes.

It has been found that film composites based on nonphotoconducting poly(vinyl butyral) doped with a Cu/Mn heterometallic complex possess photovoltaic properties in the region of absorption of this complex. Introduction of a xanthene dye into the composite leads to an increase in the absolute value of the photovoltaic response, with the sign of the response changing from negative to positive. It is assumed that for the samples with free surface of composite films without a dye, the photovoltaic effect is determined by diffusion of more mobile negative carriers (Dember effect), whereas upon introduction of the cationic dye, photogenerated positive charge carriers play a dominant role in the photovoltaic effect.

The information properties of holographic recording media for photothermoplastic recording with films of oligomer composites based on carbazolyl-containing linear and star co-oligomers with branching centers on silicon and germanium atoms have been studied. The media based on the star oligomers possess higher holographic sensitivity due to greater plasticity and ability to accumulate space electrical charge during exposure. The buildup of space electrical charge results from the capture of photogenerated holes by energy traps created by dimers formed from terminal carbazolyl groups, whose amount is larger in macromolecules of radial oligomers than in linear oligomers.

Photogeneration of electric charge carriers at high strengths of the external electric field and the temperature of transition to the viscous-flow state ( T visc ) of thin PEPC-C 60 composite films obtained by casting from a toluene solution have been studied. The rheology of the composite films has been investigated by the nondestructive optical method. The consistent correlated change in the values of T visc and the effective temperature in the expression for the photogeneration quantum yield ( T 0 ) in the Meltz representation with variations in the C 60 concentration has been established. The difference between T visc and T 0 in thin composite films does not exceed 2–3% of T visc ( T 0 ).

The dark conductivity and the photoconductive properties of polymer film composites based on polyvinyl butyral doped with various amounts of the heterometallic complex (H3O)2(H2en)[Cu(en)2(H2O)2][V10O28] · 3H2O (where en is ethylenediamine) have been studied. It has been found that the activation energy of photocurrent in the films increases with an increase in applied electric field strength. An increase in the applied electric field strength has been assumed to result in the release of charge carriers from deeper energy traps that can occur in the heterometallic complex.

Photoluminescence quenching in an external electric field increases and a long-wavelength photoluminescence band and photoconductivity appear in the visible spectrum with increasing concentration of anionic polymethine dye in poly-N-epoxypropylcarbazole films. Associated species containing dye ion pairs are formed with increasing dye concentration. The kinetics found for the growth and relaxation of the photocurrent in these composite films is anomalous for photosemiconductor materials: the time required for growth of the photocurrent is much greater than the time for its relaxation after switching off the light. A prior irradiation memory effect of the films was discovered.

We have studied the photoconducting properties of films of ferrocene-containing oligomer with additives of squarylium and merocyanine dyes based on ferrocene and tetranitrofluorene in the dye absorption region. We have studied the characteristic features of the effect of an external magnetic field on the photocurrents. After the magnetic field is turned on, the photocurrent increases in the samples with squarylium dye and decreases in the samples with merocyanine dye. We discuss the hypothesis that in the first case, as a result of an internal photoelectric effect, predominantly triplet charge pairs are formed, while in the second case predominantly singlet charge pairs are formed. The latter may be one of the reasons for the higher photoconductivity of films with squarylium dye compared with merocyanine dye.

The effect of negative photoconductivity of ferrocenyl-containing oligomer films doped with a merocyanine dye based on ferrocene and tetranitrofluorene has been found. The decrease in the conductivity current and its recovery after switching off light are in agreement with the decrease and the recovery of the dielectric loss tangent in the films studied. The phenomenological model is suggested in which the buildup of space charge from nonequilibrium current carriers and its effect on electric conductivity of the films are taken into account. It is supposed that energetic traps for nonequilibrium charge carriers are formed due to proximity of the ferrocenyl fragments in the oligomer and a long distance between its end groups.

We have studied the photoconducting and photodielectric properties of heterostructures based on poly-N-epoxypropylcarbazole and poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene] doped with zinc 2,3,9,10,16,17,23,24-octabutylphthalocyanine located between SnO 2 :In 2 O 3 and Ag electrical contacts, in the absorption region of the metal complex. We have observed that the photosensitivity is higher when the poly-N-epoxypropylcarbazole films are deposited on a SnO 2 :In 2 O 3 electrode. The increased photosensitivity of the heterostructures compared with monolayers of the films is explained by the high efficiency of dissociation of the photogenerated electron–hole pairs and the decrease in the effect of traps for nonequilibrium charge carriers at the film interfaces.

The electrical and photoconductive properties of films of the composites based on poly(vinyl alcohol) with additions of the (NH4)[Cu(en)2Fe(C2O4)3] · 2DMSO complex, which forms polycrystalline structures in the films, have been studied. The increment of the conduction current under exposure to light is independent of the application of the voltage during illumination. The kinetics of increase and relaxation of the photoinduced conductivity does not depend on the voltage and light intensity (in the ranges under investigation). The photoinduced conductivity of the films decreases in the external magnetic field. The kinetics of change in the photocurrent after turning the magnetic field on and off is similar to the kinetics of its increase and relaxation after turning light on and off. The specific features of the internal photoelectric effect and the appearance of the memory effect under exposure to light have been attributed to deep energy traps sensitive to the magnetic field.

The specific features of electric conductivity and photoconductivity in films of composites based on poly(vinyl alcohol) doped with the complex [Fe(bipy)3][Zn(NCS)4] (where bipy is 2,2′-bipyridyl) and the effect of magnetic field on these properties were studied. It was found that photocurrent decreases with an increase in the magnetic field strength up to 5.5 kOe. It was assumed that the photoconductivity of these composites and its dependence on magnetic field are affected by paramagnetic iron(III) complex particles produced as a result of internal photoelectric effect. The effect of magnetic field on the photoconductivity is associated with the spin-dependent recombination of photogenerated charge pairs.

New azo polymers and a polymeric complex with cobalt based on them were created, and the effect of interaction of the chromophores on the electrooptical effect in films of these materials was investigated. It was established that with increase in the length of the “spacer” and with the possibility of the formation of hydrogen bonds between the substituents in the azobenzene groups the time of the changes in the optical characteristics of the films decreases and their magnitude increases under the influence of the electric field. A phenomenological model of the effect of aggregates of the azobenzene groups attached to the main polymer chain by the spacers on the electrooptical characteristics of the films is proposed.

We have synthesized polymethacrylates with azobenzene side moieties and “spacers” of different lengths. We have studied the spectra and kinetics of the electro-optical effect appearing in films of such azopolymers after they are exposed to linearly polarized light. The nature of the electro-optical effect is explained by the appearance of photoinduced optical anisotropy in the films, due to a change in the ratio of the concentrations of trans and cis isomers of the azobenzene moieties. The characteristic time required for establishment and relaxation of photoinduced optical anisotropy correlates with the times required for a change in the dielectric characteristics of the studied films when exposed to linearly polarized light.

Изучены голографические, электро- и фотопроводящие свойства пленок на основе карбазолилсодержащего соолигомера с добавками 2,3,9,10,16,17,23,24-октабутилфталоцианин цинка (PcBuZn), двухпалубного фталоцианина диспрозия (Dy(Pc)2), частиц Pr2O3. Большей фотопроводимостью характеризуются пленки с PcBuZn, что обусловлено фотогенерацией долгоживущих триплетных зарядовых пар. Наличие Dy в молекулах сенсибилизатора или частиц Pr2O3 в пленках способствует увеличению их фотопроводимости, что связывается с увеличением скорости синглет-триплетной конверсии зарядовых пар.