Relaxation,Thermal, and Interphase Effects in Polymer–Ferroelectric-Piezoelectric Ceramic Composites of Different Structures

Semiconductors - The relaxation and thermal processes and interphase phenomena in composites based on ferroelectrics and a polymer matrix are studied. It is shown that the charge stabilized at the...     

A Study on the Application Model of B2B E-Commerce in the Agricultural Sector

There are two main application models of B2B e-commerce, which are best suitable for agricultural sector. One is the e-market intermediation model (EMIM), and the other is the Integrative content center model (ICCM). Based on the analysis of these two models in application field of agriculture, a conclusion is drawn that these two models will be the main application ones of agricultural e-commerce at present, while ICCM will be a transition from local e-commerce to integrative e-commerce. The future development of agricultural e-commerce will follow the direction of integrative e-commerce which is based on the supply chain model on the E-Hubs. And a new framework of integrative e-commerce is presented as a conclusion at last.     

Synthesis of 0D Manganese-Based Organic–Inorganic Hybrid Perovskite and Its Application in Lead-Free Red Light-Emitting Diode

Lead-based perovskite light-emitting diodes (PeLEDs) have exhibited excellent purity, high efficiency, and good brightness. In order to develop nontoxic, highly luminescent metal halide perovskite materials, tin, copper, germanium, zinc, bismuth, and other lead-free perovskites have been developed. Here, a novel 0D manganese-based (Mn-based) organic–inorganic hybrid perovskite with the red emission located at 629 nm, high photoluminescence quantum yield of 80%, and millisecond level triplet lifetime is reported. When applied as the emissive layer in the PeLEDs, the maximum recording brightness of devices after optimization is 4700 cd m⁻², and the peak external quantum efficiency is 9.8%. The half-life of the device reaches 5.5 h at 5 V. The performance and stability of Mn-based PeLEDs are one order of magnitude higher than those of other lead-free PeLEDs. This work clearly shows that the Mn-based perovskite will provide another route to fabricate stable and high-performance lead-free PeLEDs.     

Fishbone Diagram: Application to Identify the Root Causes of Student–Staff Problems in Technical Education

Wireless Personal Communications - Fishbone diagram, also called as ‘cause-and-effect’ diagram, is a tool used to identify the root cause of problems which represents the effect and the...     

Correction to: Fishbone Diagram: Application to Identify the Root Causes of Student–Staff Problems in Technical Education

Wireless Personal Communications - There were spelling errors in the second author’s name in the initial online publication. The original article has been corrected.     

Study of Changes in the Current–Voltage Characteristics of a Semiconductor Diode When Powerful High-Frequency Signals Pass Through It

Journal of Communications Technology and Electronics - Abstract—An experimental stand has been created to assess the characteristics of the electromagnetic field under which the...     

Schottky-Barrier Model Nonlinear in Surface-State Concentration and Calculation of the <Emphasis Type="Italic">I–V</Emphasis> Characteristics of Diodes Based on SiC and Its Solid Solutions in the Composite Charge-Transport Model

A modified Schottky-barrier model, which is nonlinear in terms of the surface-state concentration and contains a local quasi-Fermi level at the interface induced by excess surface charge, is proposed. Such an approach makes it possible to explain the observed similarity of the I–V characteristics of diodes with the Schottky barrier M/(SiC)_1–x(AlN) _x and those of heterojunctions based on SiC and its solid solutions taking into account Φ_g ≈ Φ_B. The results of calculations of the Schottky-barrier heights are consistent with the experimental data obtained from measurements of the photocurrent for metals (M): Al, Ti, Cr, and Ni. The I–V characteristics in the composite–additive model of charge transport agree with the experimental data for the n-M/p-(SiC)_1–x(AlN) _x and n-6H-SiC/p-(SiC)_0.85(AlN)_0.15 systems.     

Continuous-Wave Stimulated Emission in the 10–14-μm Range under Optical Excitation in HgCdTe/CdHgTe-QW Structures with Quasirelativistic Dispersion

Semiconductors - In two waveguide heterostructures with quantum-well arrays of Hg0.892Cd0.108Te/Cd0.63Hg0.37Te with a thickness of 6.1 nm and Hg0.895Cd0.105Te/Cd0.66Hg0.34Te with a thickness of 7.4...     

Uncooled Photodiodes for Detecting Pulsed Infrared Radiation in the Spectral Range of 0.9–1.8 μm

Semiconductors - Uncooled photodiodes based on GaSb/GaAlAsSb heterostructures for recording pulsed infrared radiation in the spectral range of 0.9–1.8 μm are developed and studied. The...     

Empirical Study of the Disparity in Radiation Tolerance of the Minority-Carrier Lifetime Between II–VI and III–V MWIR Detector Technologies for Space Applications

The degradation of the minority-carrier recombination lifetime of various III–V nBn and II–VI HgCdTe midwave-infrared space detector materials under stepwise 63-MeV proton irradiation up to fluence of 7.5 × 10¹¹ cm^?2 and above has been measured using time-resolved photoluminescence while samples were held at 120 K to limit thermal annealing. As expected, the recombination rate of each sample was found to increase with proton fluence at a nearly constant rate, implying a near-linear increase in defect concentration. The rate of change of the carrier recombination rate, herein called the minority-carrier lifetime damage factor, was then plotted as a function of the initial recombination rate for each sample. Juxtaposing the III–V and II–VI results revealed a distinct disparity, with the incumbent detector material HgCdTe being roughly an order of magnitude more radiation tolerant to displacement damage from proton irradiation than any of the nBn materials. The results for the latter also suggest some degree of interrelation between the damage factor and initial lifetime. The behavior of the lifetime of each material under annealing revealed that HgCdTe exhibited nearly 100% recovery at 295 K whereas III–V materials recovered to only about 50% under the same conditions.     

Physical Principles of Self-Consistent Simulation of the Generation of Interface States and the Transport of Hot Charge Carriers in Field-Effect Transistors Based on Metal–Oxide–Semiconductor Structures

A detailed simulation of degradation (caused by hot charge carriers) based on self-consistent consideration of the transport of charge carriers and the generation of defects at the SiO₂/Si interface is carried out for the first time. The model is tested using degradation data obtained with decananometer n-type-channel field-effect transistors. It is shown that the mutual influence of the above aspects is significant and their independent simulation gives rise to considerable quantitative errors. In calculations of the energy distribution for charge carriers, the actual band structure of silicon and such mechanisms as impact ionization, scattering at an ionized impurity, and also electron–phonon and electron–electron interactions are taken into account. At the microscopic level, the generation of defects is considered as the superposition of single-particle and multiparticle mechanisms of breakage of the Si–H bond. A very important applied aspect of this study is the fact that our model makes it possible to reliably assess the operating lifetime of a transistor subjected to the effects of “hot” charge carriers.     

Application of the inner–outer flexible GMRES-FFT method to the analysis of scattering and radiation by cavity-backed patch antennas and arrays

The finite element-boundary integral (FE-BI) method is applied for the analysis of scattering and radiation by cavity-backed patch antenna and arrays. In this investigation, the FE-BI formulations have been implemented using brick element volumes and it allows for a particular use of the efficient FFT-based iterative solver. The inner–outer flexible GMRES algorithm is applied to solve the equation with a higher convergence speed when compared with the standard GMRES algorithm.     

Determination of the Bulk Conductivity of III–V Semiconductors in a Strong Constant Electric Field and under Harmonic Effects

Semiconductors - Currently, devices in the region of the microwave and extremely high frequency (EHF) ranges are being developed using the nonlinear properties of the bulk of III–V...     

Barrier рBn-Structure Based on GaAsSb/AlAsSb/InAsSb for Detection of IR Radiation in the Spectral Range of 3.1–4.2 µm

Journal of Communications Technology and Electronics - In the study, a new рBn-architecture based on a GaAsSb/AlAsSb/InAsSb heterostructure of III‒V&nbsp;group materials with an...     

Effect of Dislocation-related Deep Levels in Heteroepitaxial InGaAs/GaAs and GaAsSb/GaAs <Emphasis Type="Italic">p</Emphasis>–<Emphasis Type="Italic">i</Emphasis>–<Emphasis Type="Italic">n</Emphasis> Structures on the Relaxation time of Nonequilibrium Carriers

The results of an experimental study of the capacitance–voltage (C–V) characteristics and deep-level transient spectroscopy (DLTS) spectra of p⁺–p⁰–i–n⁰ homostructures based on undoped dislocationfree GaAs layers and InGaAs/GaAs and GaAsSb/GaAs heterostructures with homogeneous networks of misfit dislocations, all grown by liquid-phase epitaxy (LPE), are presented. Deep-level acceptor defects identified as HL2 and HL5 are found in the epitaxial p⁰ and n⁰ layers of the GaAs-based structure. The electron and hole dislocation-related deep levels, designated as, respectively, ED1 and HD3, are detected in InGaAs/GaAs and GaAsSb/GaAs heterostructures. The following hole trap parameters: thermal activation energies (E _t ), capture cross sections (σ _p ), and concentrations (N _t ) are calculated from the Arrhenius dependences to be E _t = 845 meV, σ _p = 1.33 × 10^–12 cm², N _t = 3.80 × 10¹⁴ cm^–3 for InGaAs/GaAs and E _t = 848 meV, σ _p = 2.73 × 10^–12 cm², N _t = 2.40 × 10¹⁴ cm^–3 for GaAsSb/GaAs heterostructures. The concentration relaxation times of nonequilibrium carriers are estimated for the case in which dislocation-related deep acceptor traps are involved in this process. These are 2 × 10^–10 s and 1.5 × 10^–10 s for, respectively, the InGaAs/GaAs and GaAsSb/GaAs heterostructures and 1.6 × 10^–6 s for the GaAs homostructures.     

Surface Impedance of the “Thick Ice–Sea” Structure in the Radio Wave Range from Very Low to Very High Frequencies

Journal of Communications Technology and Electronics - In this paper, the scope of applicability of impedance boundary conditions for a vertically polarized wave in the 0.01–120 MHz frequency...     

Contribution of Auger recombination to saturation of the light-current characteristics in high-power laser diodes (λ = 1.0–1.9 m m)

Spectral and light-current characteristics of lasers based on the asymmetric separate-confinement heterostructures InGaAs/InGaAsAl/InP and InGaAs/GaAs/AlGaAs/GaAs were studied in the pulsed mode of lasing. It is shown that, at high levels of current pumping, the charge-carrier concentration in the active region of semiconductor lasers for the near-infrared optical region increases beyond the oscillation threshold; drastic saturation of the light-current characteristics is observed. Processes occurring in lasers as the charge-carrier concentration increases beyond the lasing threshold are studied theoretically. It is established that, at high pump levels, the rate of stimulated recombination decreases, the lifetime of charge carriers increases, and both the concentration of emitted photons and the quantum yield of stimulated radiation decrease. It is shown that variations in stimulated recombination, the decrease in the quantum efficiency, and saturation of the light-current characteristic in semiconductor lasers at high levels of current pumping are caused by the contribution of the nonradiative Auger recombination.