The results of a study of photoluminescence (PL) of epitaxial films of Hg0.3Cd0.7Te and Hg0.7Cd0.3Te solid solutions grown by molecular beam epitaxy are presented. A comparison of PL data with the results of optical transmission measurements and structural and microscopic studies showed that in terms of the degree of disorder of the solid solution, the studied Hg0.7Cd0.3Te films are not inferior in quality to the material synthesized by other methods. For Hg0.3Cd0.7Te films, PL data revealed significant composition fluctuations and the presence of acceptor states, which indicates the need to optimize the technology.

The results of photoluminescence (PL) study of As-doped Cd0.3Hg0.7Te solid solutions layers grown by molecular beam epitaxy on a Si substrate are presented. Analysis of the PL spectra obtained at different temperatures and excitation laser powers allows one to judge the nature of the observed peaks. The activation of arsenic in annealed samples was established, as a result of which small acceptor levels are formed. The effectiveness of arsenic as an acceptor impurity for cadmium-mercury tellurides has been confirmed.

Photoluminescence of arrays of self-induced nanowires consisting of pure InAs and of InAs diluted with nitrogen was studied in the 4.2-300 K temperature range. Formation of the hexagonal wurtzite (nanowires) and cubic sphalerite (mostly parasitic islands) crystal structure modifications was observed on a Si substrate used for the growth of the nanowires. A decrease in the band gap of both crystalline phases due to the introduction of nitrogen was established.

An Erratum to this paper has been published: https://doi.org/10.1134/S1063782624060010

This article presents the results of a study of current-voltage (I–V) characteristics of InAsSb/InAsSbP heterostructures with an InSb content in the InAsSb active region 0.06 and 0.09. Using these results, the results of electroluminescence studies, and the data of energy-dispersive X-ray spectroscopy obtained for InAsSbP films grown on InAs(Sb), it is shown that the peculiarities of formation of the InAsSb/InAsSbP heterointerface via the method of metalorganic vapor phase epitaxy can lead to the development of a type II heterojunction. At temperatures T ≤ 170 K, this is manifested in specific values of both the energy of electroluminescence spectrum maximum and the I–V cutoff value.

Subject of study. Epitaxial films of Hg0.7Cd0.3Te solid solutions grown by molecular beam epitaxy and doped with arsenic to obtain hole-type conductivity in order to form p-n junctions for the production of infrared photodetector structures are studied. Aim of study. The types and characteristics of defects formed during arsenic doping of epitaxial films of Hg0.7Cd0.3Te solid solutions grown by molecular beam epitaxy and the effect of doping on the level of disorder in the solid solution are determined. Method. Ellipsometry, optical transmittance, photoluminescence, and photoreflectance are used. Main results. The initial material is shown to have high quality in terms of film bulk and surface quality, and the quality was found to improve after two-stage activation thermal annealing. Annealing has been shown to activate the arsenic with the formation of shallow (7-8 meV) acceptor levels. No side defects were found to occur as a result of the introduction of arsenic into the films during growth and annealing. Practicalsignificance. This research demonstrated the effectiveness of doping epitaxial films of Hg0.7Cd0.3Te solid solutions with arsenic as an acceptor impurity in order to produce layers with hole conductivity during the production of photodiode structures. (c) 2024 Optica Publishing Group

The electroluminescent characteristics of the InAs/InAs1-ySby/InAsSbP asymmetric light-emitting diode heterostructures with high InSb mole fraction in the active region (y>0.09) in the temperature range 4.2-300 K have been studied. Stimulated emission was achieved in the wavelength range 4.1-4.2 μm at low temperatures (T<30 K). It was found that the electroluminescence spectra were formed as a result of the superposition of contributions from different channels of radiative recombination of charge carriers near the type II heterointerface. The effect of the quality of the type II InAsSb/InAsSbP heterojunction on the radiative interface transitions with an increase in the content of InSb in the ternary solid solution is considered. Keywords: heterojunctions, InAs, antimonides, electroluminescence, light-emitting diodes.

Photoluminescence (PL) and photoreflectance (PR) spectroscopy were used for the optical study of arsenic doping of HgCdTe grown by molecular beam epitaxy (MBE). Un-doped and arsenic-doped material with cadmium telluride molar fraction x=0.29 grown under similar conditions and subjected to similar types of annealing was studied. The PL spectra of the un-doped material featured signatures of intrinsic defects associated with mercury vacancy, excessive tellurium, and related complexes. In the arsenic-doped material, optical signatures of these defects appeared to be suppressed. After arsenic activation, shallow (7-8meV) acceptor levels were found in the material. These were attributed to the dopant activation, which was confirmed with electrical studies showing p-type conductivity with hole concentration similar to 10(16) cm(-3). The studies showed that the actual pattern of arsenic doping in HgCdTe can be indeed screened by intrinsic defects, which are inherent to MBEgrown HgCdTe and tend to interact with the dopant.

The subject of the study is epitaxial films of Hg1-x 1 - x CdxTe x Te solid solutions with the mole fraction of CdTe, x , varying from 0.3 to 0.7, grown by molecular beam epitaxy, and intended for the manufacture of photodetecting and laser structures operating in the infrared range. The aim of the study is to determine the relationship between the optical and microscopic properties of Hg1-xCdxTe 1 - x Cd x Te solid solutions with fluctuations in their composition. The methods include optical transmission, photoluminescence, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Main results. By comparing the results of optical, structural, and microscopic studies, it is shown that, for the films with x : 0.3, the research data on optical properties make it possible to adequately estimate the bandgap and determine the chemical composition of the material. The high perfection of this material is shown, and it is confirmed that its disorder is caused only by the specifics of the formation of semiconductor solid solutions. For the films with x : 0.7, it is established that data on the bandgap and composition can only be obtained from ellipsometric studies and measurements of optical transmission, whereas photoluminescence spectra at temperatures up to room temperature are formed by optical transitions involving carriers localized on large-scale composition fluctuations. In the films with x : 0.7, the presence of uncontrolled acceptor states is also detected, which may indicate the need to optimize the technology of this material. Practical significance. The limits of applicability of photoluminescence studies for characterizing the properties of solid solutions are identified. The need for further optimization of the technology of materials with large (x x : 0.7) compositions is shown. (c) 2024 Optica Publishing Group

Electroluminescence of narrow -gap n -InAs/InAs 1- y Sb y / p -InAsSbP heterostructures with the indium antimonide content in the active region y = 0.07-0.12 has been studied. A radiative recombination channel associated with the InAsSb/InAsSbP heterointerface has been discovered. The dependence of the type of this heterointerface on the actual composition of the barrier layer near the interface has been established.

Subject of study. An n-InAs/InAs1-ySby/ p-InAsSbP light-emitting diode heterostructure with an indium antimonide molar fraction (y = 0.15) for a long-wavelength (over 4 mu m) region of the mid-infrared range and epitaxial n+-InAs/InAs1-ySby films (y = 0-0.16) is studied. Aim of study. The aim is to determine the nature of optical transitions in long-wavelength InAsSb-based light-emitting diode heterostructures aimed at extension of the range of their operation to the spectral region of wavelengths over 4 mu m as well as to decrease the temperature dependence of the wavelength of the heterostructures. Method. The heterostructures under study were grown by metal-organic vapor phase epitaxy, and the light-emitting diode chip was formed by standard photolithography and chemical etching. The optical properties of the resulting structures were studied by photo- and electroluminescence methods, the chemical composition of the films was studied by energy-dispersive X-ray spectroscopy on a scanning electron microscope, and the structural properties of the films were studied by X-ray diffractometry. Main results. It is shown that the structural and optical properties of InAs1-ySby epitaxial films are mainly determined by the indium antimonide content in the ternary solid solution. A significant effect of radiative transitions involving interface states at the "film-substrate" heterointerface, as well as indirect recombination transitions at a step-like type II InAsSb/InAsSbP heterojunction in the n-InAs/InAs0.85Sb0.15/ p-InAsSbP light-emitting diode heterostructure at temperatures below 150 K on the optical properties of the structures is demonstrated. It is shown that switching of the main channel of the radiative recombination of structures makes it possible to reduce the influence of temperature on their wavelength. Practical significance. The revealed effect of switching the main channel of radiative recombination with temperature determines the prospects for the manufacture of temperature-stable light-emitting diodes for the mid-infrared range. (c) 2023 Optica Publishing Group

The paper, which consists of two parts, considers in detail the method of discrete mobility spectrum analysis (DMSA) proposed by the authors as well as its application to determine the parameters of charge carriers in CdHgTe. The first part of the work was a brief review of the existing methods for analyzing the field dependences of the Hall coefficient and conductivity in structures with a multi-carrier spectrum of charge carriers. In the second part of the work, the physical properties of the mobility spectrum envelope in the mobility spectrum analysis (MSA) method are analyzed and the main idea, features, and algorithm of the DMSA method are presented. On the example of studying the electrical properties of numerous samples of CdHgTe epitaxial films, the high sensitivity of the DMSA was confirmed. Using DMSA, we analyzed a number of dependences of the conductivity tensor components σxx and σxy on the magnetic field B, available in the literature, and compared the results of the analysis with those obtained with other methods.

The results of a study of the optical and structural properties of wide-bandgap (x~0.7) layers in laser heterostructures based on Cd x Hg 1-x Te solid solutions grown by molecular beam epitaxy on (013)GaAs substrates, as well as epitaxial films similar to these layers in chemical composition, are presented. It is shown that the position of the maximum of the photoluminescence spectrum and the nature of its temperature shift are related to the disordering of the composition of the solid solution. Shallow and deep acceptor levels were found in the bandgap. The possible influence of disordering and acceptor levels in laser structures on the energy spectrum of carriers is discussed. Keywords: CdHgTe, laser structures, photoluminescence, defects, structural properties.

The results of a study of the optical and structural properties of wide-bandgap (x~0.7) layers in laser heterostructures based on CdxHg1-xTe solid solutions grown by molecular beam epitaxy on (013)GaAs substrates, as well as epitaxial films similar to these layers in chemical composition, are presented. It is shown that the position of the maximum of the photoluminescence spectrum and the nature of its temperature shift are related to the disordering of the composition of the solid solution. Shallow and deep acceptor levels were found in the bandgap. The possible influence of disordering and acceptor levels in laser structures on the energy spectrum of carriers is discussed.

Electroluminescent (EL) properties of asymmetrical InAs/InAs1-ySby/InAsSbP heterostructures with the y = 0.09 and y = 0.11 InSb content in the active layer were studied in wide temperature range T = 4.2-300 K. The stimulated emission in the spectral range 4.1-4.2 & mu;m has been observed at low temperatures (T < 30 K). It was estimated that EL spectra were formed owing to different channels of radiative recombination depending on the ambient temperature. The influence of the quality of the type II InAsSb/InAsSbP heterojunction on radiative recombination transitions has been considered.

The electroluminescent characteristics of the InAs/InAs1−ySby /InAsSbP asymmetric light-emitting diode heterostructures with high InSb mole fraction in the active region (y > 0.09) in the temperature range 4.2−300 K have been studied. Stimulated emission was achieved in the wavelength range 4.1−4.2 μm at low temperatures (T < 30 K). It was found that the electroluminescence spectra were formed as a result of the superposition of contributions from different channels of radiative recombination of charge carriers near the type II heterointerface. The effect of the quality of the type II InAsSb/InAsSbP heterojunction on the radiative interface transitions with an increase in the content of InSb in the ternary solid solution is considered.

The results of comparative studies of the optical and structural properties of Hg0.7Cd0.3Te bulk crystals and epitaxial films grown by various methods are presented. The data of photoluminescence studies performed in the temperature range 4.2–300 K showed the similarity of the optical properties of different samples and indicated a significant disordering of the solid solution. According to X-ray diffraction data, however, the scale of the disordering was not directly related to the structural quality of the material. The prospects for using the material grown by various methods in optoelectronics applications are discussed.

The distribution function for a phonon gas in the non-equilibrium case of current crowding in a chalcogenide glassy semiconductor is considered. The approximate internal energy of the gas and its heat capacity is calculated. The change in the heat capacity caused by phase changes, which according to the results of the numerical calculations, are similar to the second-order phase transition, is analyzed. The law of temperature variation with time is calculated for a homogeneous current crowding without a heat sink, taking into account the exponential dependence of the conductivity on the temperature. It is shown that the temperature dependences of the concentration and energy of phonons do not undergo significant changes and are linear. The results of this work should be useful in developing chalcogenide glass-based phase-change memory devices, where strong heating by an electric current is possible and, as a consequence, a significant effect of phonons on the current flow should occur.

The results of studying the optical properties of gallium-nitride samples with a highly oriented texture structure, grown without using a conventional semiconductor or sapphire substrates, are presented. It is shown that the stacking faults contained in the GaN blocks in the texture of the material under study are self-organized heteropolytype nanostructures and the effective luminescence in the ultraviolet (UV) spectral range, associated with stacking faults of the I 1 type in the basal plane, is determined by the optical transitions of excitons localized near these natural defects in the single-crystal bulk of blocks in the GaN texture.

A detailed analysis of the mechanisms of radiative and Auger recombination in type I and II heterostructures based on narrow-gap AIIIBV materials is presented. It is shown that the presence of a heterointerface fundamentally changes the nature of these recombination processes differently, depending on the type of heterojunction. Results of our study of the electroluminescence of type I and II LED heterostructures based on InAs(Sb)/InAsSbP quantum wells are presented. It is shown that the increase in relative efficiency of radiative recombination in type II heterostructures due to suppression of Auger recombination contributes to generation of stimulated emission in these heterostructures at low temperatures (4.2−70K).