bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystal lattice tilt analysis in gradient composition layers by electron and X-ray diffraction
Authors: Snigirev L A , Kirilenko D A , Pirogov E.V. , Baidakova M V , Bert N A 
Published: December 2019

Abstract
The combination of X-ray tilt-azimuth figure, reciprocal space map and transmission electron microscopy in selected area electron diffraction mode was applied to analyse the tilt of the MBE-grown 1.2-μm thick convex-graded InxAl1-xAs (x=0.05-0.80) metamorphic buffer layer on singular GaAs (001) substrate. The combination of the techniques is demonstrated to enable the determination of the tilt angle as well as the tilt direction together with monitoring of the tilt development along the growth direction. For the studied metamorphic buffer layer as an example, the tilt direction was deduced to be 20° off the (110) GaAs substrate crystallographic plane. The tilt angle of (002) buffer layer planes was observed to rapidly rise to 0.6° near the layer-substrate interface and then to slowly increase to 1.4° with the approach toward the surface.
Formation peculiarities of silver dendritic structures for photocatalysts of the visible radiation range
Authors: Sigaev A P , Averin I A , Pronin I A , Karmanov A A , Yakushova N D , Moshnikov V A 
Published: December 2019

Abstract
The techniques for synthesis of silver structures in the form of a polyhedral array, as well as in the form of self-similar objects, spatially organized by the type of dendrites, are presented. The mechanisms that potentially determine the formation peculiarities of such structures are considered. Prospects of using this type of structures alongside with wide band gap semiconductor oxides, as highly efficient photocatalysts of the visible radiation range, are demonstrated.
Critical pressure during the formation of carbon nanotubes by the method of plasma chemical vapor deposition
Authors: Klimin V S , Rezvan A A , Morozova J V 
Published: December 2019

Abstract
The critical pressure of acetylene required for the formation of nanotubes on nickel catalytic centers of a given size was calculated by plasma chemical vapor deposition. It has been established that for a stable growth of carbon nanotubes on a catalytic center with a diameter of 20 nm, the critical pressure of acetylene should be 1.9 Pa, while the growth time of carbon nanotubes in length of 5 μm is 131 sec. Nickel was used as a material for the formation of catalytic centers. In the calculations, the averaged parameters of carbon nanotubes were used. This analysis allowed to form a number of criteria for the materials of the underlayer and catalytic centers, to obtain an array of carbon nanotubes with a high degree of verticality.
Application of the atomic layer etching technique for the formation of SiC-based field emitters
Authors: Klimin V S , Kots I N , Tominov R V , Rezvan A A , Varzarev Y N , Ageev O A 
Published: December 2019

Abstract
This paper presents the technology of obtaining graphene films on the surface of SiC using a combination of methods of focused ion beams and plasma-chemical etching in a fluorine containing environment. For the formation of nanoscale structures with lateral dimensions of 280 nm, the method of focused ion beams was used. Nano sized structures were formed on the surface of silicon carbide by an ion beam, which were subsequently placed in the reactor. In the reactor, the structures on silicon carbide were processed in fluoride plasma. The depth of the structures was 900 nm. SF6 was used for atomic layer etching operations. The study of the surface topology at each iteration was carried out using scanning electron microscopy. Electrical characteristics were measured by atomic force microscopy.
Combined scanning probe nanolithography and liquid etching techniques for profiled nanostructures formation
Authors: Polyakova V V , Kots I N , Avilov V I , Parshina N V , Smirnov V A 
Published: December 2019

Abstract
The results of studies of the effect of technological modes of nanoscale silicon substrate surface profiling by local anodic oxidation (LAO). The effect of relative humidity and the amplitude of the voltage applied to the tip-substrate system with LAO on the geometric parameters of the oxide nanostructures (ONS) and profiled nanostructures (PNS). It has been shown that increasing the voltage amplitude to the probe substrate 10 to the system 20 causes an increase in the height of the ONS 0.6 ± 0.2 to 2.0 ± 0.3 nm at 70% relative humidity. Investigations of the possibility of using ONS as a mask during the silicon etching liquid. It has been shown that increasing the silicon etching time from 10 to 80 seconds in the KOH + IPA causes increased silicon PNS height of 100 ± 10 nm and 350 ± 30 nm. The results can be used in the development of technological processes of manufacturing of nanoelectronics components based on silicon base using the probe nanotechnologies.
InGaN nanostructures of a branched morphology on silicon substrate: MBE synthesis and properties
Authors: Reznik R R , Kotlyar K P , Khrebtov A I , Kryzhanovskaya N V , Cirlin G E 
Published: December 2019

Abstract
A possibility of InGaN nanostructures of a branched morphology MBE growth on Si substrate has been demonstrated. The results of morphological studies have shown that InGaN synthesis occurs in several stages. InGaN nanostructures turned out to be optically active at room temperature and have a wide radiation visible range.
ZnO thin films synthesis by RF magnetron sputtering deposition
Authors: Gridchin V.O. , Kotlyar K.P. , Vershinin A.V. , Kryzhanovskaya N.V. , Pirogov E.V. , Semenov A.A. , Belyavskiy P.Y. , Nashchekin A.V. , Cirlin G.E. , Soshnikov I.P. 
Published: December 2019

Abstract
Investigation of ZnO thin films synthesis using RF magnetron sputtering deposition in the Ar/O2 plasma gas mixture at different O2 composition and at different growth temperatures is presented. The effect growth process on structural (morphology and orientation films, grain sizes, lattice parameters) and optical (transmittance, absorption, refractive index, photoluminescence) properties are examined. It is shown that synthesized ZnO thin films at a temperature from 200 to 300 °C are polycrystal and textured. Notice that ZnO thin films, which are synthesized using pure Ar plasma gas, are porosity. The optical transmittance and absorption spectra have an absorption edge near 380 nm. The PL spectra of synthesized ZnO films show exciton peaks at 370-400 nm and the wide emission at the yellow and red spectral regions.
Modeling the formation of InP/GaxIn1-xP axial nanowire heterostructures
Authors: Koryakin A A , Leshchenko E D , Dubrovskii V G 
Published: December 2019

Abstract
A model is developed to depict the formation of InP/GaxIn1-xP axial heterostructures in self-catalyzed GaxIn1-xP nanowires. The composition profiles of the InP/GaxIn1-xP axial heterostructure are calculated taking into account elastic stresses. It is shown that the InP/GaxIn1-xP axial heterojunction width at the growth temperature of 450°C is larger than 12 monolayers for nanowires with the radius larger than 10 nm. Also, the comparison with GaxIn1-xAs system is performed and reveals that the InP/GaxIn1-xP axial heterojunction width is approximately two times smaller than the InAs/GaxIn1-xAs axial heterojunction width.
Role of the wetting layer in the crystallization stage during droplet epitaxy of InAs/GaAs nanostructures
Authors: Balakirev S V , Eremenko M M , Chernenko N E , Ageev O A , Solodovnik M S 
Published: December 2019

Abstract
In this paper, we present the results of experimental study of the role of the wetting layer in the crystallization stage of droplet nanostructures in the lattice-mismatched InAs/GaAs material system. We demonstrate that the thickness of the wetting layer can significantly affect the characteristics of nanostructures formed during crystallization in the arsenic flux. While the surface density of InAs nanostructures does not increase relatively to the initial droplet density obtained at 300 °C, a significant increase of the nanostructure density is observed after crystallization of droplets obtained at 200 °C. This behaviour is attributed to the additional stress-driven Stranski-Krastanov quantum dot formation and confirmed by the 2D-3D transformation of indium layer obtained at 100 °C.
Nondestructive 3D-evaluation of human dentin by microtomography using synchrotron radiation
Authors: Gudkina Z V , Argunova T S , Gutkin M Yu 
Published: December 2019

Abstract
Results of Synchrotron Radiation (SR) microtomography of human dentin specimens subjected to compression tests are presented. A special attention is paid to cracks formed in the samples under compression. In all the samples, the dominant crack paths were observed to deviate and deflect around certain areas at or near to dentinal tubules. It is confirmed that secondary (satellite) cracks play an important role in dominant crack blunting. It is shown that microtomography is an effective method for investigation of the formation of satellite cracks and crack-tubule interactions over surface areas and across the whole depth of a dentin specimen. These processes can be visualized and evaluated using reconstructed 2D slices. A qualitative model for the formation of secondary cracks opening at stress concentrators that are dentinal tubules is suggested. It is shown that on the surface of the tubules, which are the closest to the tip of a mode II crack, the tensile circumferential stress can reach extremely high values that are more than enough for generation of secondary cracks.
Highly hydrophilic and stable polylactic acid surface achieved by argon plasma treatment
Authors: Romashkin A V , Polikarpov Yu A , Struchkov N S , Silakov G O , Petukhov V A , Levin D D , Nevolin V K 
Published: December 2019

Abstract
The effect of modifying additives such as low molecular weight polylactide (PLA) and benzyl alcohol (BA) on the degree of hydrophilicity of high molecular weight PLA before and after plasma treatment with low density and specific power per area was investigated. The lowest water contact angle (WCA) after modification was about 17°. A comparative evaluation of the formed functional groups amount, the hydrophilicity and stability of the plasma modification was carried out. WCA measurements of ageing of modified samples over time up to one year was carried out. It was found that plasma treated PLA films, obtained from tetrahydrofuran solution of high-molecular weight PLA and BA, demonstrated one of the highest ageing stability at high hydrophilicity. At the same time, the increase of the oxygen-containing functional groups amount on the modified PLA surface (about 40%, estimated by XPS) is close to the critical value in point of view of ensuring both high hydrophilicity and stability of the PLA surface after the modification.
Test object as a subject of biometric studies of eye reaction
Authors: Bikberdina N , Bobrova D , Boronenko M 
Published: December 2019

Abstract
Interest in detecting the psychophysical state of a person according to various biometric data (KGR, pupillography and profiling, etc.) is becoming more widespread every year. The most statistically reliable and resistant to counterfeiting systems are the identification of a person by the iris and face. Biometric identification systems can be combined. This paper presents proposals for improving the existing systems of recognition of the psychophysical state of a person.
Measurement and analysis of the recombination coefficients distribution on the area of light-emitting InGaN/GaN heterostructures
Authors: Frolov I V , Radaev O A , Sergeev V A 
Published: December 2019

Abstract
A method and an installation for evaluation the profile of distribution of recombination coefficients and current density over the area of light-emitting heterostructures at low injection levels based on local values of the 3 dB frequency are described. Using the example of measuring the parameters of commercial blue InGaN/GaN-based LEDs, it is shown that the current density is higher in those areas of the chip where the 3 dB frequency is lower.
Simulation of current-voltage characteristics and power-voltage characteristics of «space» solar cells based porous silicon in the Comsol Multiphysics package
Authors: Shishkin I A , Lizunkova D A , Latukhina N V 
Published: December 2019

Abstract
To analyze the characteristics of solar modules based on porous silicon involved in the flight experiment aboard a small spacecraft AIST 2D, the method of computer simulation of solar cell characteristics was used. The paper presents the procedure for developing a simulation model of photovoltaic modules in Comsol Multyphysics. The developed model allows us to investigate the current-voltage and voltage-watt characteristics of solar modules and determine the main parameters. The discrepancy between the experimental data obtained from the telemetry data from the AIST-2D with the simulation results does not exceed 5%.
Spectral analysis of the electroluminescence and photoresponse of heterostructures with InGaAs quantum objects
Authors: Salii R A , Evstropov V V , Mintairov S A , Mintairov M A , Shvarts M Z , Kalyuzhnyy N A 
Published: December 2019

Abstract
In this work, physical and optical properties of In0.8Ga0.2As quantum dots (QDs) embedded in the structure of a single-junction GaAs solar cell (SC) grown by MOVPE technique were investigated using spectral characteristics of external quantum yield (EQE) and electroluminescence (EL). It has been found that, in characterizing QD physical parameters, simplified model of a thin stressed quantum well can be applied to a wetting layer (WL). It has been demonstrated that the EL spectra allows determining the absorption energy of photons in WL and QDs more accurately compared to the EQE spectra. Energies of “Ee-Ehh” and “Ee-Elh” transitions in WL have been determined and were 1.325 eV and 1.388 eV respectively. The calculated values of the WL thickness (5.63 Å) and In composition of QDs (xIn = 80%) coincide with the technological parameters used in the epitaxial growth of the device.
Φ-OTDR based on tunable Yb-Er:phosphate-glass laser
Authors: Choban T V , Zhirnov A A , Chernutsky A O , Stepanov K V , Pniov A B , Galzerano G , Karasik V E , Svelto C 
Published: December 2019

Abstract
In recent times, phase-sensitive optical time domain reflectometers became widely common for monitoring of extended objects and providing necessary measurements in optical telecommunications. In this paper we present our investigations and results in the development and characterization of a new type of laser for phase-sensitive optical time domain reflectometry.
Stabilizing effect of injection in broad-area lasers
Authors: Yarunova E A , Krents A A , Molevich N E , Anchikov D. A. 
Published: December 2019

Abstract
In this paper, spatiotemporal dynamics of broad-area lasers with external optical injection is investigated. We demonstrate theoretically that relatively small optical injection suppresses unstable transverse modes and stabilizes laser output. In this paper, the general case of a mismatch in the frequency of the radiation injected and generated by a laser was numerically investigated. It is shown that the frequency mismatch does not destroy the stabilizing effect.
Polarization properties of single-walled carbon nanotube thin film on silicon substrate in terahertz frequency range
Authors: Kvitsinskiy A , Demchenko P , Litvinov E , Masyukov M , Anoshkin I , Vozianova A , Khodzitsky M 
Published: December 2019

Abstract
Terahertz time-domain spectroscopic polarimetry (THz-TDSP) method was used to study of polarization properties of a randomly oriented single-walled carbon nanotube (SWCNT) thin film on a silicon (Si) substrate in terahertz (THz) frequency range under an external optical pumping (OP) and an external static magnetic field (MF). Frequency dependencies of azimuth and ellipticity angles of a polarization ellipse and the polarization ellipse at various frequencies of the Si substrate and the SWCNT thin film on the Si substrate were obtained experimentally. The results confirm the fact that, based on carbon nanotubes, it is possible to devise efficient tunable THz polarization modulators for use in the latest security and telecommunication systems.
Study of the effect of carbon nanotube lengths on their conductivity in the terahertz frequency range during optical pumping
Authors: Baimagambetova R , Gomon D , Demchenko P , Anoshkin I , Khodzitsky M 
Published: December 2019

Abstract
In this work, the conductivity of carbon nanotubes with the different lengths with / without optical pumping in the frequency range of 0.2 - 1 THz was experimentally studied. The results show that the restructuring of the geometric properties of carbon nanotubes will allow to create THz devices with tunable spectral characteristics.
Numerical simulation of a nitride single quantum well laser
Authors: Medvedeva E E , Konoplev S S , Savelyev A V 
Published: December 2019

Abstract
Numerical simulation of a quantum well on nitrides, optical interband transitions in low dimensional semiconductor structures (semiconductor quantum wells), conduction-heavy hole and transitions in quantum wells, refinement of the gain for a quantum well on nitride materials with allowance for the overlap integral and approximate this.
Large active area superconducting single photon detector
Authors: Moshkova M , Morozov P , Divochiy A , Vakhtomin Yu , Smirnov K 
Published: December 2019

Abstract
We present development of large active area superconducting single-photon detectors well coupled with standard 50 μm-core multi-mode fiber. The sensitive area of the SSPD is patterned using the photon-number-resolving design and occupies an area of 40×40 μm2. Using this approach, we have obtained excellent specifications: system detection efficiency of 47% measured using a 900 nm laser and low dark count rate of 100 cps. The main advantages of the approach presented are a very short dead time of the detector of 22 ns and FWHM jitter value of about 130 ps.
Gold nanoantennas for enhancement of photon emission from STM contact
Authors: Shkoldin V A , Permyakov D V , Golubok A O , Uskov A V , Samusev A K , Mukhin I S 
Published: December 2019

Abstract
Inelastic electron tunneling in a tunnel junction may be used as an electrical nanosource of surface plasmon polaritons and photons. In this work, we investigate emission from tunnel contact between the Platinum/Iridium tip and a thin Au film on glass. The experiment has shown that the intensity of this emission can be enhancement by use a gold nanoantenna located in the vicinity of tunnel contact.
Second harmonic generation and charge relaxation of poled glasses
Authors: Reshetov I V , Kaasik V P , Lipovskii A A , Tagantsev D K 
Published: December 2019

Abstract
We measured thermal relaxation of the second order nonlinearity (SON) observed in a thermally-poled soda-lime silicate glass. It is shown that 50-min annealing of the glass at 400°C results in a complete SON degradation. Performed studies of thermo-stimulated depolarization current (TSDC) revealed that the poling-induced spatial electric charge relaxes above the glass transition temperature. This indicates that SON is not induced by this spatial charge.
Investigation of optical properties of In(Ga)As/GaAs mesa structures with active region based on quantum wells, quantum dots, and quantum well-dots
Authors: Dragunova A S , Kryzhanovskaya N V , Maximov M V , Mintairov S A , Kalyuzhnyy N A , Moiseev E I , Mukhin I S , Tikhomirov V G , Zhukov A E 
Published: December 2019

Abstract
In this work photoluminescence (PL) of mesa-structures that contain three different types of active regions based on InGaAs/GaAs quantum wells (QWs), InAs/InGaAs/GaAs quantum dots (QDs) and InGaAs/GaAs quantum well-dots(QWD) is studied. Comparative analysis of the PL intensity obtained at different temperatures and optical excitation powers on mesa diameter is done.
The influence of iron concentration on the cathodoluminescence kinetics in the mid-IR range in ZnSe:Fe crystals
Authors: Chukichev M , Rezvanov R , Chegnov V , Chegnova O , Mironov S , Gladilin A , Il’ichev N , Kalinushkin V 
Published: December 2019

Abstract
Integral intensity and kinetics dependences of cathodoluminescence of ZnSe:Fe crystals in mid-IR spectral range was studied. Concentration of iron varied from 0.01 to 14 wt.%. The experiments were carried out in 77 - 300 K temperature range. It is established that the luminescence pulse rise time is longer than excitation pulse at low iron concentration at 77 K temperature. The increasing ones lead to shortening of the luminescence pulse rise time, decreasing of the luminescence lifetime and increasing of the luminescence intensity in mid-IR. The annealed ZnSe:Fe concentration series in vapour Zn are reproduced the same trends. The nature of observed experimental effects is discussed.
SERS induced by Au/ZnO plasmonic nanorods coupled to Au nanoparticles
Authors: Kaydashev V. , Zolotukhin P. , Belanova A. , Anokhin A. S. , Minasyan T. , Chernishev A. , Kaidashev E. M. 
Published: December 2019

Abstract
We study the surface enhanced Raman scattering of Methylene Blue (MB) dye molecules induced by 3D array of “hot spots” made of vertical Au/ZnO core-shell nanorods coupled to self-assembled plasmonic Au nanoparticles. SERS substrates based on array of nanorods coupled to nanoparticles show much better performance compared with bare Au/ZnO nanorods. The hybrid 3D SERS substrate perfectly resolve Raman spectra of MB molecules chemisorbed from solutions with analyte concentrations of ∼10-7 M even upon washing of a sample i.e. when only chemisorbed molecules were remained. Raman signal enhancement results from the superposition of two effects, namely, the ability of a plasmonic coupled system to enhance the Raman scattering via local field enhancement and from the large 3D surface which provides more adsorption sites compared with traditional 2D surfaces.
Numerical Analysis Spectral Huygens Filter for pulsed broadband Terahertz Radiation
Authors: Liu X , Petrov N V , Kulya M S , Tsypkin A N , Grachev Ya V , Kozlov S A 
Published: December 2019

Abstract
In this paper, we consider a Huygens filter for a specified frequency lying within a broad spectrum of a pulsed THz radiation which represents simplest two-zone plate. The condition of the infinite plane wave and the Gaussian beam are separately used as the initial source has been discussed. A property method of terahertz spectral filter has been explored.
The influence of optical density change on measurement error of refractive index in flowing liquid
Authors: Grebenikova N M , Davydov V V , Rud’ V Yu 
Published: December 2019

Abstract
The article discusses the physical processes in a flowing fluid that affect the change in its optical density. Changes in the refractive index and its errors in single-component and multicomponent media for different fluid flow regimes are investigated. A new model has been developed for calculating error of refractive index, considering the non-uniformity of optical density in a stream liquid. A technique is proposed for selecting a refractometer model for reliable monitoring the state of liquid environment.
Mobility of a two-dimensional electron gas in the AlGaN/GaN heterostructure: simulation and analysis
Authors: Volcheck V , Stempitsky V 
Published: December 2019

Abstract
At temperatures higher than the room temperature, a two-dimensional electron gas (2DEG) formed at the AlGaN/GaN heterointerface can be characterized by the three dominant scattering mechanisms: acoustic deformation potential, polar acoustic phonon and polar optical phonon scatterings. An analytical model describing the 2DEG mobility limited by these scattering mechanisms as a function of the carrier concentration and the temperature was developed and integrated into a device simulator package using a C language interpreter. The model should be useful for heterostructure device simulators such as Blaze.