Abstract The processes of crystallization of amorphous germanium films of various thicknesses and multilayer germanium/silicon nanostructures under isothermal annealing (T = 440°C) were studied. Samples were grown on glass substrates using the method of plasma-chemical deposition. The phase composition of the structures was determined from the analysis of Raman spectra. It was found that 200 nm thick

Abstract Photodiodes based on solid solutions in the GaSb–InAs system are for the first time applied to study the spectral characteristics of single and coupled whispering-gallery-mode (WGM) lasers emitting in a range of 2.2–2.3 μm. The capacity of photodiodes with a photosensitive area 2.0 mm in diameter is C = 520 pF at U = –2 V, which corresponds to a time constant of τ = 53 ns. It is shown that

Abstract The emission properties of Ge layers grown on Si(001) substrates and doped with Sb to different levels are studied by means of steady-state and time-resolved photoluminescence spectroscopy. It is shown that the peak of the steady-state photoluminescence intensity of n-Ge/Si layers at room temperature is observed at an Sb concentration close to the level of the equilibrium solubility of Sb

Abstract Recent experimental and theoretical data on modification of the atomic and electronic structures of the surface of different III–V semiconductors by electrolyte solutions are reviewed. The interrelation between chemical reactions occurring at semiconductor/electrolyte interfaces, the charge transfer between the semiconductor and the solution, and corresponding modifications of the atomic and

Abstract The atomic and electronic structures of reconstructions with the symmetry (2 × 4), (4 × 2), c(4 × 4), and (4 × 3) on the (001) surface of GaSb and InSb semiconductors are investigated by the projector augmented-wave method. It is shown that the reconstruction β2(2 × 4) is stable on the GaSb(001) surface in the cation-rich limit, while the α2(2 × 4) reconstruction has the lowest energy in the

Abstract A method is developed for analyzing spontaneous-emission modification in cylindrically symmetric structures. A matrix method is developed for cylindrical structures. General expressions for the radiative-recombination rate are derived for an emitter placed at any point on the structure. Quantitative indicators for estimating radiative-recombination enhancement and suppression are determined;

Abstract Gallium-nitride nanorods with a diameter of 15–40 nm and length of 50–150 nm are synthesized in monodisperse spherical mesoporous silica particles (MSMSPs) by high-temperature annealing of the Ga2O3 precursor in ammonia. The template material (a-SiO2) is selectively removed by etching the composite MSMSP/GaN particles with HF to give individual GaN nanorods. It is shown that the size of the

Abstract A new Pd|HfO2|AlGaN|GaN metal-oxide-semiconductor (MOS) enhancement-mode high electron mobility transistor (HEMT) is fabricated with low-temperature sensitization, activation, electroless-plating, and two-step gate-recess approaches. Experimentally, a high positive threshold voltage Vth of 1.96 V, a very low gate leakage IG of 6.3 × 10–8 mA/mm, a high maximum extrinsic transconductance gm

Abstract A model of a heterostructure consisting of a silicon-carbide single layer formed on a massive silicon substrate is proposed. The problem of the adsorption of alkali metal atoms and halogen atoms on the carbon and silicon surface atoms of a 2D SiC/Si heterostructure is considered. Analytical estimates for charge transfer and the adsorption energy are reported.

Abstract Some of the III–V semiconductor used in various devices suffer from the surface high density of states limiting their application. This study compares and evaluates five different ammonium sulfide passivation methods on GaAs surface with the aim to enhance the electrical characteristics of Au|n-GaAs Schottky junction. Wet chemical passivation of the n-GaAs surface was carried out by dipping

Abstract We analyze the asymmetric delta-doping dependence of nonlinear electron mobility μ of GaAs|InxGa1 –xAs double quantum-well pseudo-morphic modulation doped field-effect transistor structure. We solve the Schrodinger and Poisson’s equations self-consistently to obtain the sub-band energy levels and wave functions. We consider scatterings due to the ionized impurities (IMP), alloy disorder (AL)

Abstract The growth of AlGaInSbAs solid solutions on InAs substrates from the liquid phase in a temperature-gradient field is discussed. The calculation of parameters is performed, and the luminescence properties and spectral characteristics of AlGaInSbAs solid solutions isoperiodic to InAs substrates are investigated. The heterophase equilibria in the Al–Ga–In–Sb–As system are analyzed in the scope

Abstract The behavioral features of the spectra of impedance components and electric module for copper-doped polycrystalline zinc-sulfide layers are investigated. The dispersion of the frequency dependences of the electrical parameters corresponding to the distribution of the relaxation time is established. An equivalent sample circuit that includes a constant phase element and describes electric transport

Abstract The impedance and capacitive properties of Pd/oxide/InP structures are investigated at 300 K in the frequency range of 10–1–10–5 Hz in air and in a nitrogen–hydrogen gas medium. The characteristics of structures in both media are interpreted based on a parallel RC-chain model with series resistance. The structure resistance decreases in the presence of hydrogen by three orders of magnitude

Abstract The results of studying the frequency and temperature dependences of the ac electrical conductivity of FeGaInSe4 crystals are presented. It is found that the systematic feature σ ∝ f s (0.1 ≤ s ≤ 1.0) is satisfied for the electrical conductivity at the temperatures under study in the frequency range f = 5 × 104–106 Hz. The activation energies are determined from the temperature dependences

Abstract Resistive-type structures based on gallium-oxide films are studied. The Ga2O3 films are produced by radio-frequency magnetron-assisted sputtering of a β-Ga2O3 (99.9999%) target onto unheated sapphire substrates with preliminarily deposited platinum electrodes. The data on the structure and phase composition of the films are obtained immediately after sputtering and after annealing in argon

Abstract In a particular case of Au-catalyzed InxGa1 –xAs nanowires, wide compositional tuning has been obtained using metal organic vapor-phase epitaxy, which remains difficult for molecular beam epitaxy. InxGa1 –xAs nanowires are demonstrated with x = 0.5, grown by Au-catalyzed molecular beam epitaxy via the vapor–solid–solid mode at a low temperature of 220°C. Low-temperature growth suppresses re-evaporation

Abstract The spectroscopic ellipsometry method is used to investigate the optical properties of PbSe nanostructured thin films formed by the chemical deposition method. Function d2ε/dω2 formed by numerical differentiation of experimental data of the dielectric function ε/ω is used for better structural resolution of the interband transitions and the determination of critical points. Theoretical fitting

Abstract The equilibrium transport of atomic carbon between the Rh surface and bulk, which controls the kinetics of the phase transition resulting in graphene growth or destruction, is investigated. The difference between the activation energy Es1 of atomic-carbon dissolution and the energy E1s of its segregation from the bulk to the surface is found to be ΔE = 0.7 eV. The temperature dependence of

Abstract The effect of annealing of a CH3NH3PbI3 organometallic perovskite film on its electrical, photoelectrical, and optical properties is studied. It is shown that annealing at the temperature Ta > 140°C results in the formation of a two-phase structure consisting of perovskite and lead iodide, whose relative content depends on the conditions of annealing, specifically, on the annealing temperature

Abstract Silicon light-emitting diodes with luminescence associated with (113) defects are fabricated by the implantation of 350-keV oxygen ions at a dose of 3.7 × 1014 cm–2 and subsequent annealing at 700°C for 1 h in a chlorine-containing atmosphere. The electroluminescence is studied in wide temperature and excitation-power ranges. The line associated with the (113) defects is dominant in all the

Abstract The impact of carrier gas on the GaN layers properties grown by atmospheric pressure metal-organic vapor-phase epitaxy (AP-MOVPE) on (001) and (11n) GaAs substrates were investigated. The Arrhenius plots of growth rate deduced from laser reflectometry measurements give an activation energy of Ea1 = 0.045 eV when the H2 was used as the carrier gas. In the case of using N2 as the carrier gas

Abstract A model is developed that makes it possible to analytically determine the threshold current of a microdisk laser with consideration for its self-heating as a function of the ambient temperature and the microlaser diameter. It is shown that there exists a minimum microdisk diameter determined by self-heating, up to which continuous-wave lasing can be reached at a given temperature. Another

Abstract Ni2+-doped ZnO thin films were prepared for various Ni concentration on the porous silicon substrates. The residual stress in the ZnO thin film is relaxed with increase in the concentration of Ni. FESEM images show the growth of pillar-like nanostructures over the entire porous silicon substrates. The variation of resistivity due to UV illumination was observed for the Ni-doped ZnO thin films

Abstract The radiation doping of single-crystal silicon with phosphorus retains the structure of the sample, reduces internal stresses, and increases the lifetime of minority charge carriers. The study is concerned with the effect of phosphorus additives on the electronic properties of silicene. The electron density-of-states spectra of a phosphorus-doped single layer and 2 × 2 bilayer silicene on

Abstract Charge transport in (TlGaSe2)1 –x(TlInS2)x solid solutions in the frequency range of 20–106 Hz before and after γ irradiation is studied using impedance-spectroscopy methods. The relaxation character of the permittivity dispersion and the nature of the dielectric loss are established. The frequency dependence of the dissipation factor tanδ in the crystals of the (TlGaSe2)1 –x(TlInS2)x solid

Abstract The measured electrical parameters of silicon pin photodiodes subjected to the implantation of defect-forming ions and subsequent heat treatment are analyzed, which reveal a new way of reducing the dark current and enhancing the device yield. The data of the electrical measurements are compared with the results of the structural study. The experimental efficiency of proton irradiation of the

Abstract The kind of profile produced during the reactive ion etching of AlGaInN light-emitting-diode (LED) heterostructures on the surface that became free after removal of the growth substrate is studied in relation to the composition of the gas mixture used in the etching process. It is shown that using a mixture composed of Cl2 and Ar, taken in a 3:2 ratio in terms of flow rates, leads to the thinnest

Abstract The effect of uniaxial elastic deformation on the current–voltage characteristic of surface–barrier Sb–p-Si〈Mn〉–Au diodes is studied. It is shown that reverse-current sensitivity to uniaxial compression exceeds the forward-current sensitivity at identical applied voltages. An increase in the forward current of these structures during deformation is caused by internal gain associated with redistribution

Abstract Minimizing the impact of radiation-induced degradation in dilute nitride based optoelectronic devices is crucial in its applications. The effects of 1-MeV electron irradiation (of 1 × 1014–1 × 1016 e/cm2 range) on undoped GaInNAs|GaAs single quantum-well (QW) structure has been studied by low-temperature photoluminescence (PL). PL spectra of GaInNAs|GaAs QW are measured before and after electron

Abstract The polarization processes in thin layers of amorphous molybdenum disulfide MoS2 are studied by dielectric spectroscopy techniques. The process of dipole-relaxation polarization is observed. The microscopic parameters of the system are calculated, and the relaxation time of the dipole-polarization process, as well as the activation energies Ea and Eσ of the relaxation process and conductivity

Abstract Solutions of (Zn, Pb, Mn)S quantum dots with different molar ratios between cations are produced by colloidal synthesis in a methyl methacrylate (MMA) medium. By the thermal polymerization of MMA in a block, the colloidal solutions are converted into the vitreous state. The optical transparency of the poly(MMA)/(Zn, Pb, Mn)S composites at the wavelengths >500 nm reaches 90% at a thickness

Abstract The effect of a set of quasi-neutral regimes of carrier transport in semiconductors, including, along with diffusion and drift, recently discovered diffusion stimulated by quasi-neutral drift, on the characteristics of structures is successively taken into account. The order of change in the carrier transport regimes in Schottky-diode structures is investigated and the features in the I–V

Abstract A set of structural and spectroscopic methods of diagnostics is used to study the influence of a nanoporous silicon (por-Si) transition layer on the practical implementation and specific features of growth of GaN layers on SiC/por-Si/c-Si templates by molecular-beam epitaxy with the plasma activation of nitrogen. It is shown that a por-Si transition layer introduced into a template, in which

Abstract Using the Green’s function method within the tight-binding approximation, the electronic structure of an infinite silicon-carbide sheet, and nanoribbons and one-dimensional chains cut from it, is considered. Analytical expressions for band gaps, electron effective masses and characteristic velocities are derived. The effect of metal and dielectric substrates on the band characteristics is

Abstract This paper presents the Ultrasonic Spray Pyrolysis system fabrication of gallium-doped zinc oxide (ZnO:Ga)|cuprous oxide (Cu2O) thin film hetero-junction. The deposition parameters were constant for ZnO:Ga and Cu2O. Structural and optical properties of ZnO:Ga, Cu2O, and ZnO:Ga|Cu2O hetero-junction were characterized by X-Ray Diffraction method and UV–Vis spectrometry, respectively. SEM and

Abstract The possibility of predicting the magnitude of the trapped charge in the buried oxide of silicon-on-insulator structures using the Poole–Frenkel effect is investigated. The conditions for the Poole–Frenkel effect in this layer are determined by measuring and modeling the current–voltage characteristics of buried silicon oxide at various temperatures. Processes occurring in the buried oxide

Abstract A lumped model of the dynamics of the controlled switching of high-Q closed-mode structures in rectangular large cavities (up to 1 × 1 mm and larger) based on AlGaAs/InGaAs/GaAs laser heterostructures is presented. The model considers the modulation of the useful power of a closed-mode structure due to controlled generation switching to an alternative closed mode. Generation-switching control

Abstract Experimental studies of n+-GaAs/n0-GaAs/n+-GaAs isotype heterostructures with a 100-nm-thick wide-gap N0-AlGaAs barrier situated in the n0-GaAs region are carried out. It is shown that the current–voltage characteristic of the structures under study has a negative-differential-resistance (NDR) portion, with the transition to this region occurring with a time delay that may reach tens of nanoseconds

Abstract In this paper, a novel silicon carbide (SiC) super-junction U-shape metal-oxide semiconductor field-effect transistor (UMOSFET) with an integrated hetero-junction diode (HJD) is proposed and investigated using numerical simulations. The integrated HJD substantially improves body diode characteristics and reduces switching losses without degrading the static characteristics of the device. In

Abstract Multilayer integrated porous membranes are obtained in a monolithic frame containing two types of porous silicon: macroporous silicon with pore diameters up to 10 μm and channel silicon with channel diameters from 100 to 300 nm. A laboratory technology is proposed for preparing macroporous/channel silicon two-layer structures with the use of high-resistance n-Si substrates (1 Ω cm). The pore-formation

Abstract A 2D carrier transport model to be used in studying the spatial current dynamics in laser thyristors is presented. The model takes into account such features as optical feedback, impact ionization, and drift velocity saturation in strong electric fields. It is shown that there is current localization during laser-thyristor switch-on. A relationship is demonstrated between the distribution

Abstract Ge-based metal-oxide semiconductor structures exhibiting thin ALD-grown high-k dielectric HfO2 films were fabricated and characterized chemically, structurally, and electrically. X-ray photoelectron (XP) spectroscopy confirms the good stoichiometry of the ALD-grown HfO2 films. Furthermore, through the analysis of the XP spectra, the conduction and valence band offsets of HfO2|p-Ge were calculated

Abstract The thermoelectric properties and crystallization kinetics of Cr0.26Si0.74 thin films with the thicknesses 11, 14, 21, 31, 56, 74, and 115 nm are studied. The films are produced by magnetron-assisted sputtering onto a cold substrate and, in the initial state, are amorphous in structure. During thermal annealing, the amorphous mixture transforms into a two-phase nanocrystalline composite consisting

Abstract This paper highlights the temperature factor in the experimental study of total absorption as a method for experimental validation and the study of the exciton–polariton light transfer mechanism near the fundamental absorption edge in semiconductor crystals with spatial dispersion. The results of experimental studies of temperature-dependent total exciton absorption are generalized. The experimentally

Abstract The effect of preliminary weak illumination at elevated temperatures on the photoelectric properties of undoped α-Si:H films is investigated. It is found that the dark conductivity and photoconductivity of films increases with the preliminary-illumination intensity, and the parameter γ determining the dependence of the photoconductivity on the illumination intensity decreases due to an increasing

Abstract Doping II–VI semiconductors and low-dimensional structures based on them by manganese leads to the effective quenching of electroluminescence and photoluminescence under the condition that the electron excitation energy of the crystal exceeds the energy of the intracenter transition of the Mn2+ ion EMn ≈ 2.1 eV. Quenching implies effective energy transfer from a photoexcited crystal to Mn2+

Abstract The current–voltage characteristics measured on Ge2Sb2Te5 thin films in the current mode are studied. The effect of multilevel recording is established when applying sequential current pulses with increasing maxima. It is shown that this effect can be associated with memory-channel expansion. The memory-channel size is estimated. It is concluded that Ge2Sb2Te5 films can be used as memristors