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81.
A. D. Grishina T. V. Krivenko V. V. Savel’ev R. W. Rychwalski A. V. Vannikov 《High Energy Chemistry》2013,47(4):187-191
The photoelectric and photorefractive characteristics of polyvinylcarbazole (PVK) composites with 0.15 wt % graphene at a wavelength of 532 nm have been measured. The dependence of the quantum efficiency of generation of mobile charge carriers as determined from the photocurrent is well approximated by the Onsager equation calculated accurate to E 0 3 for the quantum yield of thermalized electron-hole pairs of φ0 = 1 and their initial separation radius of r 0 = 10.9 Å. The long-wavelength edge of optical absorption for PVK lies at 365 nm. Thus, the photogeneration of mobile carriers during illumination of the composite at 532 nm is due to photoexcitation of graphene. The measurement of the photorefractive properties has revealed that the two-beam coupling gain coefficient is Γ = 50 cm?1 at E 0 = 150 V/μm and equal intensities of incident beams. It has been found that at E 0 = 83.3 V/μm, the two-beam coupling gain coefficient increases from 8 to 14 cm?1 as the ratio of incident beam intensities I 1(0)/I 2(0) increases from 1 to 2.4. 相似文献
82.
Abstrac - In this letter the model of diffusion-limited reactions has been applied to account for the formation rates of HA, HZ and V4 centers after a fast electron pulse, as reported by Saidoh et al (ref. 4). 相似文献
83.
V. A. Kolesnikov O. N. Babenko V. I. Zolotarevskii A. V. Vannikov 《High Energy Chemistry》2006,40(1):44-48
Single-layer and dual-layer xerographic photoreceptors based on polyvinylcarbazole, a novolac resin, and the pyrocatechol violet dye were studied. The single-layer photoreceptors exhibited an order of magnitude higher photosensitivity as compared with their dual-layer counterparts. It was found that the character of conductivity decay in a photoreceptor after positive or negative corona charging of its outer surface depended on the technological conditions of substrate pretreatment. 相似文献
84.
E. L. Aleksandrova V. M. Svetlichnyi L. A. Myagkova N. V. Matyushina T. N. Nekrasova R. Yu. Smyslov V. D. Pautov A. R. Tameev A. V. Vannikov V. V. Kudryavtsev 《Optics and Spectroscopy》2013,114(5):737-750
The energy structure and nature of intramolecular charge transfer have been determined for a series of synthesized 2,6-polyphenylquinolines (PPQs) containing resorcinol, oxygen, and phenylamine bridging groups between phenylquinoline cycles and possessing an arylene radical in the form of alkylated derivatives of carbazole or indolo[3,2-b]carbazole, as well as arylated derivatives of carbazole with nitro- and fluorine substituents. The analysis was based on data on their absorption spectra, photosensitivity, carrier photogeneration quantum efficiency, and luminescence. It is shown that the PPQ monomeric unit is a composite intramolecular charge-transfer complex (ICTC) between the donor arylene fragment and the acceptor quinoline cycle; the latter, in turn, is an ICTC between the donor bridging group and quinoline ring (when acceptor fluorine or nitro substituents are introduced into the carbazole structure, the complex becomes ternary), and the narrowest band gap (2.3 eV) corresponds to the PPQ having a phenylamine bridging group and a fragment of indolo[3,2-b]carbazole. 相似文献
85.
A. P. Tyutnev V. S. Saenko A. V. Vannikov Yu. F. Kundina E. D. Pozhidaev 《High Energy Chemistry》2000,34(2):80-88
The salient features of charge transport in a typical molecularly doped polymer (polycarbonate + 30 wt % DEH hydrazone) were
studied by time-of-flight and nonsteady-state radiation-induced conductivity measurements. It was shows that the mobility
of holes (major carriers) is due to dispersive transport in the temperature range 296–353 K covering the glass transition
temperature at an observation time of up to a few seconds. The appearance of a plateau on the current transient, presumably
manifesting the establishing of quasiequilibrium (Gaussian) transport, is the artifact of the time-of-flight technique when
the charge carrier generation takes place at the sample surface. All of the obtained results can be satisfactorily rationalized
in terms of the Rose-Fowler-Weisberg model with a uniform set of parameters of the model. Such an approach is compatible with
the basic concepts of the radiation chemistry of condensed phase (the Onsager theory and the Langevin recombination mechanism),
structural features of a disordered medium (transport zone, structural traps), and rotational diffusion of small molecules
or their molecular groups in vitrified polymers. 相似文献
86.
Abstract Radiation-induced latchup in commercially available junction-isolated integrated microcircuits is reported. Four different types of construction of integrated microcircuits have been examined. They include quadruplediffused, diffused collector, epitaxial, and epitaxial with buried layer (gold-doped). It was found that pnpn switching could be obtained between isolated components on these devices. In fact, pnpn paths were quite common in all but the last type mentioned. The current gains of the parasitic transistors involved in these pnpn paths were measured and were, in most cases, shown to indicate that pnpn switching should occur. However, important exceptions were seen. Latchup between these isolated components could be induced by a pulse of ionizing radiation even with a reverse bias on the substrate of the microcircuits. As a result of this investigation, it is concluded that the pnpn mechanism, since it is so common, is a majorcause of latchup in junction-isolated integrated microcircuits. 相似文献
87.
88.
Ivanov V. F. Gribkova O. L. Cheberyako K. V. Nekrasov A. A. Tverskoi V. A. Vannikov A. V. 《Russian Journal of Electrochemistry》2004,40(3):299-304
A template oxidative polymerization of aniline in aqueous solutions containing poly-(2-acrylamido-2-methyl-1-propanesulfonic acid) and ammonium persulfate yields a polyaniline complex with the polyacid soluble in water. According to the data of spectral measurements, the process of polymerization is of a pronounced autocatalytic nature. The consequences of this are both the formation of a nonuniform distribution of oxidized and nonoxidized fragments of the polymer chain and the formation of a macroscopic scale of redox nonuniformities in the reaction volume during the process of polymerization. The spectra of absorption of the polyaniline/polyacid films on transparent glass electrodes with a conductive layer of SnO2 and the data of potentiodynamic measurements in the potential region 0–1.0 V (Ag/AgCl) are typical for polyaniline with moderate electroconduction. 相似文献
89.
O. L. Gribkova A. A. Nekrasov A. A. Isakova V. F. Ivanov A. V. Vannikov 《Russian Journal of Electrochemistry》2006,42(10):1085-1092
The electrochemical matrix polymerization of aniline in the presence of poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA) is performed in conditions that lead to the formation of an interpolymer complex comprising polyaniline and PAMPSA of the 1: 2 composition. The acceleration of the process of polymerization of aniline in the presence of PAMPSA as compared with traditional electropolymerization of aniline in hydrochloric acid is caused by the association of aniline molecules with the sulfo groups of PAMPSA and by a high concentration of hydrogen ions in the vicinity of a molecule of PAMPSA. It is established for the first time ever that, in the initial stages of synthesis for both polymeric and low-molecular-weight acids, the rate of polymerization is substantially greater at a smaller concentration of the acid. The distinguishing feature of the initial stage of electropolymerization of aniline at a low acidity of the environment is a non-autocatalytic character of the process, which may exert a discernible influence on a complex of physicochemical properties of polyaniline, including electric conduction. Studying spectroelectrochemical properties of the obtained films shows practical identity of their spectra with the spectra of standard polyaniline. 相似文献
90.
A. D. Grishina L. Ya. Pereshivko L. Licea-Jimenez T. V. Krivenko V. V. Savel’ev R. W. Rychwalski A. V. Vannikov 《High Energy Chemistry》2008,42(5):378-384
The photoelectric, nonlinear optical, and photorefractive characteristics of polymer composites made from unplasticized polyvinylcarbazole (PVK) and single-wall carbon nanotubes containing surface oxygen groups (at C:O ratio of 77.8:22.2%) were analyzed. The dependences of the quantum efficiency of charge-carrier generation on the applied electric field E measured at 1064 and 1550 nm coincide and are approximated by the Onsager equation expanded to the E 4 term, at π0 = 0.012 and r 0 = 9.8 Å. The third-order optical nonlinearity determined by the EFISH technique at a nanotube content of 0.26 wt % is 2 × 105 pm2/V2 or 2.3 × 10?29 C4 m/J3 in SI units. The pattern of photorefractive kinetic curves indicates that the mean free path of holes is longer than the mean range of electrons. The photorefractive net gain coefficient of the signal beam measured at 1064 nm in a field of E = 170 V/μm is Γ ? α = 55 cm?1 (α = 10 cm?1 is the optical absorption coefficient at 1064 nm). At 1550 nm, the net gain coefficient measured in a field of E = 265 V/μm is Γ ? α = 55.7 cm?1 (α = 3.3 cm?1 at 1550 nm). In the presence of oxygen groups, there is no transfer of electrons photogenerated in carbon nanotubes to the external acceptor C60. This effect can be associated with an increase in the ionization potential of nanotubes by almost 0.8 eV as a result of oxidation. 相似文献