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.

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.

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.

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.

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 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.

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).

We study in detail the mechanisms of radiative and Auger recombination in type-I and type-II heterostructures based on III–V narrow-gap materials. The presence of a heterointerface fundamentally changes the nature of these recombination processes with respect to the bulk material differently, depending on the type of heterojunction. Studying the electroluminescence of type-I and type-II light-emitting diode (LED) heterostructures based on InAsSb/InAs(Sb,P) quantum wells is presented. An increase in the relative efficiency of radiative recombination in the type-II heterostructure due to the suppression of Auger recombination favors the formation of intense stimulated emission in such heterostructures at low temperatures (4.2–70 K).

The results of a study in the temperature range 4.2–300 K of the current–voltage characteristics of light emitting diode (LED) heterostructures with an active region based on InAsSb solid solutions and InAsSb/InAs or InAsSb/InAsSbP quantum wells (QWs) are presented. The carrier-transport mechanisms depending on the temperature and heterostructure design are determined. It is shown that charge transport across the heterostructures is governed by the diffusion and recombination mechanisms at temperatures close to 300 K; in the temperature range 4.2–77 K, the contribution of the tunneling mechanism is observed. For an InAs/InAs/InAs0.15Sb0.31P0.54 heterostructure, an additional carrier-transport channel is observed. It is shown that the presence of 108 InAs0.88Sb0.12/InAs QWs in the active region leads to an increase in leakage currents across the heterojunction in the whole temperature range, which is likely related to carrier tunneling.

The results of the study of optical and structural properties of epitaxial InAs layers grown on an n-InAs substrate, and spectral and electrical properties of light-emitting diode (LED) heterostructures with an InAs active layer and various design and chemical composition of barrier layers are presented; the properties of heterostructures were studied in the temperature range 4.2−300 K. A significant influence of the degree of substrate doping and the properties of heterointerfaces on the form of emission spectra and power characteristics of heterostructures is shown. The mechanisms of the carrier transport are studied, and the prevalence of the diffusion component of the current at temperatures above 200 K and the presence of the tunneling component at lower temperatures are shown.

Твердые растворы InAs(Sb) являются важными материалами для устройств, работающих в средневолновом (3-5 мкм) инфракрасном диапазоне [1]. В этом диапазоне лежат полосы поглощения, связанные с фундаментальными вращательными и колебательными резонансами большого числа технологически важных молекул, обнаружение которых требуется для решения задач зондирования атмосферы и контроля за окружающей средой, безопасности, обороны, энергоаудита, медицины, сельского хозяйства и т.д. [2]. Светодиоды с активной областью на основе InAs(Sb) уже применяются в устройствах, предназначенных для газоанализа, управления технологическими процессами, медицинской диагностики и т.д. Одной из важных задач, стоящих перед разработчиками этих устройств, является повышение их эффективности. Это особенно важно для длинноволновых (λ>5 мкм) светодиодов, поскольку увеличение содержания сурьмы в эпитаксиальном слое InAsSb приводит к сильному рассогласованию параметров кристаллических решеток слоя и подложки. В настоящей работе мы сообщаем об исследовании оптических и структурных свойств эпитаксиальных пленок InAsSb с мольной долей InSb от 0 до 0.166, выращенных на подложке n-InAs, легированной до концентрации электронов n≈2×1018 см-3 , и предназначенных для изготовления светодиодных структур. Для сравнения также исследовались свойства пленки Ga0.24In0.76As0.78Sb0.22; подобный материал может применяться для создания барьерного слоя в светодиодных гетероструктурах.

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 4.2−300K 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 results of a study of the current-voltage characteristics of LED heterostructures with an active region based on InAsSb solid solutions and InAsSb/InAs and InAsSb/InAsSbP quantum wells (QWs) in the temperature range 4.2–300 K are presented. The mechanisms of the carrier transport depending on the temperature and design of the heterostructure was determined. It is shown that the charge transport through the heterostructures is governed by the diffusion and recombination mechanisms at temperatures close to 300 K; in the temperature range 4.2–77 K, the contribution of the tunnelling mechanism was observed. For heterostructure InAs/InAs/InAs0.15Sb0.31P0.54 the additional channel of the carrier transport was determined. It was shown that the presence of 108 QWs InAs0.88Sb0.12/InAs into the active region of the heterostructure led to an increase in the leakage currents through the heterojunction in the whole temperature range, which is probably related to the tunnelling of charge carriers.

A study of the electroluminescence of asymmetric InAs/InAs1 – ySby/InAsSbP light-emitting diode heterostructures with a molar fraction of InSb in the ternary solid solution in the active region y = 0.15 and y = 0.16 in the temperature range 4.2–300 K is reported. It is found on the basis of experimental data that a staggered type-II heterojunction is formed at the InAs1 – ySby/InAs0.41Sb0.28P0.40 heterointerface. It is shown that interfacial radiative transitions at the type-II heterointerface make a dominant contribution in the temperature range of 4.2–180 K. This enables minimization of the temperature dependence of the operating wavelength of a light-emitting diode.