The scaling of the traditional silicon MOSFETs, which are the basic devices of modern electronics, had resulted already in the channel length of 5 nm order. However, its further miniaturization faces the obstacles of fundamental nature: electrons in the ultra-short channels are tunneling freely through the barrier, and the current in the source-drain circuit is no longer governed by the gate...
X-ray image detectors have been developed for medical and non-destructive testing applications. This study shows the improvement of the resolution of the scintillator, which is an indirect conversion type X-ray image detector. The emission of the scintillator is diffused and the spatial resolution of detector is reduced. Therefore, the scintillator was optically separated using silicon that...
CdTe semiconductor has been used as radiation detectors at room temperature. Impurity doping of CdTe has been considered difficult because it requires high temperature heat treatment and characteristics are degraded. However, the laser doping method that we have recently developed is overcoming this problem. When doping semiconductors, not all dopants act as donors or acceptors, and some of...
Imaging using X-rays is currently used in a wide range of fields such as medical, industry and security.The most common type of detector in use today is the indirect conversion method.In the indirect conversion method, X-rays are converted into visible light by a material called a scintillator. In the indirect conversion method, X-rays are converted into visible light by a substance called a...
This presentation focuses on functional nanomaterials with good surface plasmon resonance properties including Ag and conductive F/Sb doped SnO2 nanoparticles synthesized via facile chemical routes. Ag nanoparticles (NPs) with the size less than 10 nm were fabricated in TiO2-SiO2 photosensitve composite film showing prominent SPR absorption spectra at around 350-500 nm with its peak at 410 nm....
In this work, ZnO rod/film homojunction structure was fabricated on Sb-doped ZnO film. The Sb-doped ZnO films were prepared by sol-gel spin coating technique onto the ITO substrate then annealed in nitrogen, air and argon followed by low-temperature hydrothermal process to obtain ZnO rod structure. The morphology of Sb-doped ZnO film exhibit the ZnO nanoparticle with smaller and increasing...
Mn and Fe-incorporated BiVO4 nanoparticles with different doping contents were synthesized via one-step sonochemical method. XRD results show the essential structure of monoclinic BiVO4 structure and secondary phases were clearly found in form of metal-based oxide as MnO, Mn3O4, Mn2O3 and Fe2O3 compounds suggesting the incorporation of Mn and Fe ions. In addition, the effect of higher Fe...
**In present report the recent results on studies of structural properties of chalcogenides glasses (CG), and their application in holographic recording are reviewed. The changes of optical, thermal and other properties of chalcogenide glasses and functional materials structures on their base are connected with changing of the structure. XRD, EXAFS, AFM, SEM techniques and Raman spectroscopy...
Raman spectroscopy is a fast, sensitive, and non-destructive technique for exploring semiconductor nanocrystals fabricated by various methods. Selective probing of electronic and vibrational spectra of different parts of heterogeneous NCs such as core-shell systems by tuning the excitation wavelength in resonant Raman scattering is considered. The analysis of phonon spectra is applied for...
Compounds of ternary (I-III-VI) and quaternary (I-II-IV-VI) metal chalcogenide nanocrystals (NC) are promising materials for photodetectors and absorber layers of thin-film solar cells of the new (third) generation, fluorophores and low-toxic fluorescent labels for biomedical applications, photocatalytic devices, supercapacitors, and other energy conversion and storage devices. The advantages...
Materials with metal-to-insulator phase transition occurring under the external biasing have an unprecedented potential in control of electromagnetic radiation in a wide frequency range from microwaves to the visible. The focus of this talk is numerical demonstration of how the space of material parameters is connected with the space of functionality at far- and mid-infrared frequencies. The...
Filamentation of femtosecond laser pulses leads to a variety of spectacular nonlinear phenomena like broadband THz generation, pulse self-compression, guiding of electric discharges and lasing effects. In particular, a coherent emission at 391.4 nm is observed from plasma filaments corresponding to a transition between levels B and X of the singly ionized Nitrogen molecule. To explain the...
The V4O7 material is one of the correlated vanadium oxides with non-trivial metal-insulator transition (MIT) behavior. This oxide belongs to Magneli phases (VnO2n-1, n=3,4,…,9) and shows reversible MIT at temperature Tc~237K. Similar to other vanadium oxides, V4O7 shows exotic electronic, magnetic, and optical properties due to strong electron-electron correlations. Here we report on...
Spintronics is the thriving field of research with the aim to control the electron spin degree of freedom for potential applications in computing, storage and memory, and fundamental science. Spintronic devices are promising in terms of lower power consumption, higher information density, and non-volatility compared to conventional electronics. However, in order to utilize the electron spin to...
Laser-induced thermal emission (LITE), generated by light-absorbing objects heated up to incandescent temperatures with nanosecond laser pulses of moderate power, is observed in the visible range of optical radiation spectrum. LITE is a kind of secondary emission which is sensitive to the structure of the irradiated surface layer. The techniques based on thermal emission observation are...
In the medical fields and industrial fields, color reproduction, which reproduces the same colors on displays as those seen by humans, is important. The standard for imaging equipment called UHD, has features such as high resolution, wide color gamut, and high dynamic range compared with standard for HD. With the color gamut has increased from HD to UHD, the saturation of primary colors of...
X-ray imaging technology has been applied in medicine, non-destructive testing in industrial sites, and security inspection in airports. Nowadays, semiconductor detectors are widely used as radiation detectors. Since semiconductor detectors convert X-rays directly into electric charges, they are said to have higher spatial resolution than scintillator detectors, which convert X-rays once into...
Non-destructive testing is routinely performed in factories. This is essential for quality assurance of products and prevention of serious accidents. Among the various non-destructive testing methods that exist, radiographic transmission testing is suitable for inspecting scratches and structures inside objects. Neutrons, a type of radiation, have a higher penetration power into metals than...
Ge detectors are widely used as X/γ detectors, but they need to be cooled by liquid nitrogen, so semiconductor detectors that can operate at room temperature are being studied as an alternative. Typical materials are CdTe and TlBr, which have the advantages of room temperature operation and higher stopping power than Ge. However, compared to Ge, which has been used in practical applications...
The noise analysis and its decreasing technology for CT-imaging is very important problem. Especially this basic studies should be applied by using Mathematical analysis, ①the stochastic Process and ②the Logistic Pure Chaos. In this presentation I wish to explain only about ② .
“Logistic Pure Chaos” represents the new fundamental constructed concept that occurs in the dynamical systems of...
Today, X-ray imaging is applied in the medical, industrial, and security fields.
In the transmission image of X-ray imaging, a detector must be placed on the opposite side of the X-ray source across the subject, which limits the size of the subject that can be captured due to the distance between the X-ray source and the detector. In backscatter X-ray imaging, on the other hand, the X-ray...
Black silicon is the focus of the research interest of many scientists around the world, both in terms of studying its fundamental properties and in connection with the emerging prospects for a wide range of applications. Interest in this material, which has a small (up to 1%) reflection coefficient in the visible range, is associated with the prospects of creating a new generation of...
Theoretical investigation on optical self action effects of intense q-Gaussian laser beams interaction with collisionless plasmas have been investigated in detail. Emphasis is put on investigating the dynamics of beam width and axial phase of the laser beam. Effect of the ellipticity of the cross section of the laser beam also has been incorporated. Using variational theory based on Lagrangian...
Nanofluid is a colloidal solution of particles with a size of (0.1-100) nm in a liquid solvent. Due to their unique physicochemical properties, nanofluids are considered promising materials for electronics, energy, pharmaceuticals, etc. The great value of the surface energy of nanoparticles contributes to their tendency to aggregation. Therefore, nanofluids are very unstable. Their properties...
The significant potentialcattributed to multilayer films consisting of alternating layers of ferromagnetic 3d-transition metal and a noble metal exists because of, such used as sensitive sensors. Besides the sarouses interest in elucidating the nature of changes in optical properties of such systems during their transformations from some island structure to a continuous one while their...
Strongly scattered amplifying media are sources of stimulated emission and consequently random lasing (RL). These environments are very convenient, but effects at their boundaries can lead to different behaviors of the emission. Competing processes that depend on the boundaries properties can both catastrophically weak or significantly enhance the emission making RL impossible or highly...
KFeO2 magnetic nanoparticles, which are biocompatible and have a relatively high saturation magnetization are considered as promising heat mediators for magnetic hyperthermia applications. In this work, we study aging effects in KFeO2 nanoparticles and show that they change their structural characteristics over time. As-produced KFeO2 nanoparticles synthesized by sol-gel technique have been...
We present a direct experimental evidence for photogeneration of the electric current from dissociated water molecules using a new class of catalytic materials - binary layered metals (BLM) with layered graphite-like structures [1-3]. BLM consists of alternative layers of metals (Al, Mg, Cr, etc.) and metalloids (B) where the ionic (covalent) exchange between layers results in alternating...
Molybdenum disulfide is due to electrical and optical properties, MoS2 can replace silicon and even graphene in the next generation nanoelectronics devices and represents new opportunities for flexible electronics. Quantum dots cadmium telluride CdTe is the most consistent for research together with MoS2 due to its high photo stability and long photoluminescence decay time.
In this work, we...
Photoelectric properties of a two monolayer thick (indirect-gap) MoS2 flake with lateral Ag contacts on a SiO2/Si substrate were studied. Photocurrent spectra were obtained with AC technique using a lock-amplifier at temperatures from 10 to 290 K. Apart from a band due to Si substrate, a contribution of MoS2 reveals in the spectra as a broad background of band-to-band transitions and sharp...
Acoustic emission (AE) allow to receive the additional information about the process of miсrocracks. Poisson coefficient μ is equal to ratio of relative transversal compression ε┴ to relative longitudinal lengthening ε║.
Complex elastic module of polyamide (NH(CH2)5CO)n, polyethylene (C2H4)n, polyvinyl chloride (C2H3Cl)n, porous polystyrene C8H8 nanocomposite Е* is equal to the sum of...
An experimental study of the spatial distribution of the light intensity of the diffraction pattern was performed by two methods: the method of photography and the method of a moving photodetector. Using the Wolfram Mathematica software package, the spatial intensity distribution of the diffracted Gaussian beam diffracted on the slit and the round hole due to Fresnel diffraction was...
Cellulose is one of the most common biopolymers. It has high strength, flexible, and has the transparency in the optical range. Also, cellulose is very ecology and refers to renewable resources. Carbons nanostructure is low-size structures that carbon in the basic. They can be used to create high-strength conductive wires or to create nano sorbents that filter water and air. They are also used...
For the necessities of the integrated optoelectronics it is extremely necessary creation of light sources of submicron sizes that would be made on the same layer with other optical elements. This possibility is provided by sol-gel technology which allows making hybrid organic-inorganic films with optical parameters that vary depending on their composition and manufacturing technology. These...
Theoretical investigation on nonlinear interaction of intense Bessel-Gauss laser beams with plasma with axial temperature ramp has been presented. Emphasis is put on investigation of self action effects of the laser beam like self focusing, self channelling and axial phase shift of the laser beam. Optical nonlinearity of the plasma has been modelled by the ponderomotive force acting on the...
Optical fiber has become the most widely used transmission medium for high speed applications. However, the standard fiber has several limitations such as chromatic dispersion ...
In order to overcome these limitations, air / silica microstructured fibers (FMAS) appear with original propagation properties. These FMAS consist of a periodic arrangement of air channels parallel to the direction...
Abstract —Sensors have known a global growth in the market regarding the different technologies. Depending on the nature of the phenomenon to be detected, there are biological, chemical and physical sensors. The optical sensors are an important example that defines the physical sensors. The sensors in integrated optics present an excellent alternative for the detection of a physical...
Abstract—The main objective of this search is, to study the photonic crystal fibers; we were interested in the characterization of optical photonic crystal fiber’s properties by studying the impact of geometric distortions on chromatic dispersion and attenuation.
It will first be a question of giving a definition of these fibers which present a new category of waveguide and have advantages...
Optical fibers are widely used in data transmission systems due to their ability to transfer massive amounts of data and their dielectric nature. It is a critical component of the worldwide broadband network infrastructure.
Optical fibers offer a vast and unique transmission bandwidth with very low latency. With Multiple wavelengths per optical fiber network topologies are utilized in...
Due to the increase in the number of mammograms performed in recent years it‘s still difficult for expert radiologists to provide accurate and consistent analyses. Over the past 20 years, diagnostic support tools have taken a remarkable place in the medical and research sector. Several research studies have been developed either to automatically detect deseases (micro-calcifications or...
The conventional continuous wavelet transform (CWT) requires considerable power and time when analyzing long signals. In order to increase the speed of computation we used CWT analysis based on Fast Fourier Transform (CWTFT), this method provides results for long recordings of phonocardiogram signals (PCG) in a short time. The analysis of the CWT depends on the mother wavelet function, in this...
The mechanisms of the photoelectric response of Ge electron-hole junction with GeSn thin films are investigated. The shape of current-voltage characteristics of the p-Ge/i-GeSn/n-Ge heterojunctions, measured in the temperature range 10–200 K, was analyzed using a two-diode model, which involves the influence of diffusion and recombination currents. The analysis of the temperature dependence of...
