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Zakharychev E.A.,Novgorod State University | Ryabov S.A.,Novgorod State University | Zefirov V.L.,Sedakov Research Institute of Measuring Systems | Semchikov Y.D.,Novgorod State University | And 3 more authors.
Inorganic Materials: Applied Research | Year: 2013

Radio-absorbing properties of polymer composite materials with carbon nanotubes (CNT) are studied in the extremely high frequency (EHF) range. The possibility is shown of producing radio-absorbing materials (RAMs) with CNT efficiently absorbing electromagnetic radiation (EMR) in the range of 52-73 GHz at thicknesses 15-30 times smaller as compared with materials containing traditional fillers, such as technical carbon and graphite. It is shown that absorbing properties analogous to the materials containing traditional fillers are reached by composites with CNTs at a significantly lower reflection coefficient on the interface boundary. An advantage of RAM fabrication using mechanical mixing as compared to ultrasonic treatment is considered. © 2013 Pleiades Publishing, Ltd.


Filatov D.O.,Novgorod State University | Gorshkov A.P.,Novgorod State University | Volkova N.S.,Novgorod State University | Guseinov D.V.,Novgorod State University | And 5 more authors.
Semiconductors | Year: 2015

We investigate the photosensitivity spectra of photodiodes based on Si p-i-n structures with single-layered and multilayer self-assembled GeSi/Si(001) nanoisland arrays in the i region, which are grown using a technique combining Si molecular-beam epitaxy and Ge vapor-phase epitaxy, in dependence on the temperature, diode bias, and GeSi nanoisland parameters. We show that the temperature and field dependences of the diode photosensitivity in the spectral range of the interband optical absorption in GeSi nanoislands are determined by the ratio between the rate of emission of photoexcited holes from the nanoislands and the rate of the recombination of excess carriers in them. We demonstrate the possibility of determination of the hole recombination lifetime in GeSi nanoislands from the temperature and field dependences of the photosensitivity. © 2015, Pleiades Publishing, Ltd.


Gus'kova O.P.,Sedakov Research Institute of Measuring Systems | Vorotyntsev V.M.,Novgorod State University | Abrosimova N.D.,Sedakov Research Institute of Measuring Systems | Shobolov E.L.,Sedakov Research Institute of Measuring Systems | Mineev M.N.,Sedakov Research Institute of Measuring Systems
Inorganic Materials | Year: 2012

We have studied the effect of ionizing radiation on MOS/SOI structures with a fluorine-ion-implanted buried insulator layer. Analysis of their high- and low-frequency capacitance-voltage characteristics indicates that the fluorination of the buried insulator ensures a substantial reduction in the density of surface states and accumulated charge at the silicon/silica interface after exposure to ionizing radiation. © Pleiades Publishing, Ltd., 2012.


Gus'kova O.P.,Nizhny Novgorod State Technical University | Vorotyntsev V.M.,Nizhny Novgorod State Technical University | Abrosimova N.D.,Sedakov Research Institute of Measuring Systems | Mikhaylov A.N.,Novgorod State University | And 2 more authors.
Physics of the Solid State | Year: 2015

The incorporation of fluorine atoms into the silicon dioxide lattice upon F+ ion implantation and the formation of silicon (germanium) nanocrystals in SiO2 upon Si+ (Ge+) ion implantation have been numerically simulated. The calculations for F have been performed by the density functional theory (DFT) method; the calculations for Si and Ge have been carried out by combining the DFT (in the cluster approximation) and Monte Carlo methods. The energy gain of the fluorine atom attachment to one of silicon atoms with the formation of a nonbridging oxygen hole center (NBOHC) and an energy level appearing in the band gap has been demonstrated. In the case of ion implantation, the simulation at a dissolved Si (Ge) atom concentration of ∼2 at % has revealed the formation of nanocrystals (NCs) with an average size of ∼1 nm. © 2015, Pleiades Publishing, Ltd.


Vorotyntsev V.M.,Novgorod State University | Shobolov E.L.,Sedakov Research Institute of Measuring Systems | Gerasimov V.A.,Sedakov Research Institute of Measuring Systems
Inorganic Materials | Year: 2011

We demonstrate that the structural perfection of silicon layers on sapphire can be improved through high-temperature solid-state recrystallization after preamorphization of the most imperfect silicon layer near the silicon/sapphire interface by high-energy oxygen ions, followed by high-temperature recrystallization in an inert atmosphere. © 2011 Pleiades Publishing, Ltd.


Shengurov V.G.,Novgorod State University | Chalkov V.Y.,Novgorod State University | Denisov S.A.,Novgorod State University | Alyabina N.A.,Novgorod State University | And 7 more authors.
Semiconductors | Year: 2015

The fabrication of photodetectors for the wavelength range of communications λ = 1.3–1.55 µm on the basis of Ge/Si(001) heterostructures with thick (~0.5 µm) Ge layers grown by the hot-wire technique at reduced growth temperatures (350°C) is reported. The single-crystal Ga layers are distinguished by a low density of threading dislocations (~105 cm–2). The photodetectors exhibit a rather high quantum efficiency (~0.05 at λ = 1.5 µm and 300 K) at moderate reverse saturation current densities (~10–2 A cm–2). Thus, it is shown that the hot-wire technique offers promise for the formation of integrated photodetectors for the wavelength range of communications, especially in the case of limitations on the conditions of heat treatments. © 2015, Pleiades Publishing, Ltd.


TRISQD software is developed for the computer simulation of processes in which radiation defects are formed under the corpuscular irradiation of semiconductor heterostructures with lenticular nanoinclusions of various shapes. The computer program is used to study defect-formation processes in p-i-n diodes with the i region having a built-in 20-period lattice of self-assembled Ge(Si) nanoislands formed under irradiation with high-energy neutrons. It is found that the fraction of Ge(Si) nanoislands in which point radiation defects are formed under the impact of atomic-displacement cascades is ≤3% of their total number in the lattice. More than 94% of the defects are localized in the bulk of the p, n, and i regions of the diode and in silicon layers that separate sheets of Ge(Si) nanoislands. © 2015, Pleiades Publishing, Ltd.

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