Search

A study on the formation of InGaN ternary compounds in the three-dimensional growth mode is presented. For the first time, we demonstrate that the self-organization during InGaN growth is responsible for the formation of core–shell nanowires (NWs), nanotubes, zinc blende (ZB) phases, and nanoflowers. It is found that the core–shell InGaN NWs are formed at the very initial stage of growth. An increase in growth time results in the ascending indium diffusion from the cores of NWs and their accumulation at the NW tips, enabling three-dimensional lateral growth and formation of nanotubes. Further nanostructure growth leads to the formation of nanoflowers with empty stems and ZB/wurtzite (WZ) phase interface at the periphery. The observed structural transformations of NWs are supported by transmission electron microscopy and photoluminescence measurements, as well as theoretical estimates. Understanding the formation mechanisms of these complex three-dimensional nanostructures can facilitate the development of InGaN compounds for gas-sensing applications. [ABSTRACT FROM AUTHOR]

The growth of nanoscale columnar AlxGa1-xN/AlN heterostructures on the surface of silicon substrates using plasma-activated nitrogen molecular-beam epitaxy was investigated in this work. Silicon substrates include atomic-smooth cSi substrate, Si substrate with a transition layer of porous silicon porSi/cSi and a hybrid substrate involving a silicon carbide layer grown with matched substitution of the atoms on the surface of porous silicon SiC/porSi/cSi. A complex analysis performed using a set of structural and spectroscopic techniques demonstrated that the epitaxial growth of the nuclear AlN layer on all types of the substrates in a N-enriched environment resulted in the formation of AlxGa1-xN/AlN heterostructures with a Ga-polar surface, which was realized only on the SiC/porSi/cSi substrate. The layer of AlxGa1-xN on cSi and porSi/cSi substrates was in the state of disordered alloy with an excess of gallium atom content. It was shown that a great difference in the lattice parameters of a substrate–film pair resulted not only in the appearance of a number of various defects but also in a considerable effect on the chemical process of the formation of the alloys, in our case, the AlxGa1-xN alloy. It was shown that nanoscale columns of AlxGa1-xN formed on SiC/porSi/cSi substrate were inclined relative to the c-axis, which was connected with the features of the formation of a SiC layer by the matched substitution of the atoms on the porous Si substrate, resulting in the formation of the inclined (111) SiC facets at the boundary of the (111) Si surface and pores in Si. Optical studies of the grown samples demonstrated that the optical band-to-band transition for the AlxGa1-xN alloy with Eg = 3.99 eVB was observed only for the heterostructure grown on the SiC/porSi/cSi substrate. A qualitative model is proposed to explain the difference in the formation of AlxGa1-xN layers on the substrates of cSi, porSi/cSi and SiC/porSi/cSi. The results obtained in our work demonstrate the availability of using SiC/porSi/cSi substrates for the integration of silicon technology and that used for the synthesis of nanoscale columnar AlxGa1-xN heterostructures using plasma-activated molecular-beam epitaxy with a nitrogen source. [ABSTRACT FROM AUTHOR]

The level of competitiveness of the mining industry is determined primarily by productivity and operational excellence. Digitalization is becoming a determining factor that will enable companies in this field to remain competitive in the future. In the mining industry, the transition to new, more advanced working methods is usually slower due to the scale and complexity of production processes, as well as due to the significant volumes of technological modernization costs. Therefore, some enterprises in this area are not actively using digital technologies. Nevertheless, the world's leading mining companies are investing heavily in the development of modern energy and automation technologies in order to increase production and environmental efficiency, reduce the use of manual labor and energy expences. It is becoming clear that digital technology is opening up new opportunities to dramatically increase productivity and profit margins. The article examines the main directions of digital transformation of mining enterprises, reveals the main opportunities and threats.

The paper analyzes the dynamics of socio-economic indicators of the development of coal-mining regions of Russia. The aim of the study is to analyze the socio-economic situation of coal-mining regions and determine the factors that influenced the social processes in the region. Based on statistical data for the period from 2010 to 2019, there was conducted the analysis of changes in economic indicators such as: income of the population; gross regional product per capita; nominal average monthly wage; unemployment rate; the proportion of the population with incomes below the subsistence level; housing commissioning in the regions. Analysis of the data showed that the most favorable social position of all the analyzed coal-mining regions is observed in the Sakhalin region. The “outsiders” in terms of social status among the coal-mining regions are the Trans-Baikal Territory and the Kemerovo Region. Improvement of the social situation in coal-mining regions is associated with the adoption by the Russian Government of a program to combat poverty, an increase in social payments to certain categories of citizens, an indexation of old-age pensions, etc. It was also revealed that social processes in the regions are influenced by prices for hydrocarbons on the world market and objective economic phenomena such as business cycles.

The role of the mining industry in the world economy is enormous, since its branches are the most important source of industrial raw materials, without which the intensive growth of modern industry would be completely impossible. However, the technologies used in it are not always innovative. Despite the fact that the mining industry occupies a fairly small percentage in the structure of the world economy and does not exceed 10%, it is an important source of income for many states, including Russia. However, the changes that are now observed in the global economy require new approaches to organizing activities. Despite its profitability, this industry is quite difficult to manage. The way from the extraction of raw materials to their end user is very complicated and depends on many conditions. For the successful integration of the Russian mining industry into new economic realities, it is necessary to intensify innovative processes by investing financial resources in new equipment and high technology. At the same time, acceleration of the development of the mining industry can be achieved in the chain “mining industry - processing industry” through the introduction and use of nanotechnology, which can significantly improve the quality of raw materials.

Currently, the economic development of an industry or type of activity cannot be considered in isolation from the spatial component. Any organization is located in some territory. It has to interact not only with suppliers and consumers, but also with the population that lives in this territory. Therefore, the economic efficiency of the activities of any organization is directly related to the social-and-economic situation of a particular space, territory. The regions in which mining enterprises are located and systemically important are no exception. These organizations belong to the “technological periphery”. New technological solutions, which are the core of economic development for new industries and some of the traditional industries, come here with a delay. Moreover, for many of their consumers, their products are not in demand. And the consequence of this is not only the economic problems of the enterprise, but also the social problems of the region or settlement. The article considers the problem of functioning for these enterprises and regions in the conditions of a new technological structure.

The mining industry belongs to the leading sectors of the global economy. However, the technologies used in it can not always be called innovative. This is due to both the specifics of the industry and the general technological lag of Russian economy. At present, it is almost impossible for individual enterprises to achieve significant success apart. In order for the process of innovative technological development to proceed more intensively, it is necessary to consider it through the prism of the ecosystem, i.e. a set of participants and the corresponding environment of this process, allowing to achieve a synergistic effect. The concept of an innovative ecosystem is based on the triple helix model, which is in turn based on a partnership between the state, science and business. They can interact effectively on the basis of technopark structures, which are a key element of the modern innovation ecosystem. The study was conducted on the basis of the Kemerovo region – a region in which a significant part of the Russian mining industry is concentrated. One of the tools for implementing the ecosystem approach to managing the development of the mining industry should be the main element of the innovation infrastructure of the Kemerovo region – the Kuzbass Technopark.

The development of a continuing vocational training programme at the Information Satellite Systems Joint-Stock Company (ISS JSC) during the transition from the planned Soviet economy to what is now called the Russian market economy is briefly outlined. How the collapse of a planned economy led to the degradation of engineering higher education (HE) is shown. The present system of engineering HE is criticized as a degraded relic of the Soviet one and an argument is made in favour of continuing vocational training in businesses like the ISS JSC, where the engineers are engaged in innovative activities. The schematic programme of training, retraining and improving the professional skills of the company's personnel is presented. Some work assignments of the centre for personnel management at the ISS JSC are examined, in particular the preparation of target students along the "school-HE-industry" chain. (Contains 1 table and 4 figures.)

This paper proposes a new type of substrate for manufacturing LEDs based on AlInGaN heterostructures. Instead of depositing SiC layers on the surface of Si using the conventional method, a new method involving the coordinated substitution of atoms (MCSA) to form the SiC layer is proposed. This new approach enables the growth of epitaxial GaN layers with low defect content and facilitates transfer to any surface. The paper details the technology of manufacturing LEDs on SiC/Si substrates obtained by the MCSA and elaborates on the benefits of using these substrates in LED production. Additionally, the advantages of the growth interface between SiC and Si materials are discussed. Moreover, it is found that thinner SiC layers (<200 nm) contribute to the scattering of the LED's own radiation in the heterostructure waveguide, which decreases its absorption by silicon. For flip-chip LEDs with the substrate removed, substrates with thicker SiC layers (~400 nm) and a growth porous layer of several microns at the SiC-Si interface is utilized to simplify Si substrate removal and enhance the manufacturing process's cost-effectiveness. [ABSTRACT FROM AUTHOR]

The problem of technological creativity in Russia is briefly discussed. Special attention is paid to the development of indigenous engineering corpus in unfavourable conditions and some reasons for engineers' low creativity are revealed. The Soviet system of engineering higher education (HE) is criticised as not focused on fostering creative engineers and the existing HE system as a degraded relic of the Soviet one. Continuous education and training in advanced corporations engaged in innovations seems better suited for preparing engineers.

The increasing role of human capital, knowledge and high technology indicates the formation of a new stage of economic development – the knowledge economy, from which innovation becomes an integral part of business. However, in terms of innovation development, Russia lags behind the western countries several times. At the same time, the development of Russian regions is extremely uneven. First, it concerns mining regions. For analysis, a key mining cluster of Russian Federation was chosen – Kemerovo Region. The article assesses the innovative potential of the region, and identifies the most pressing problems that impede its integration into the knowledge economy. Solving existing problems should be carried out through a set of measures aimed at developing partnerships of government, mining science and mineral resources extracting business, creating conditions for attracting and retaining highly qualified specialists to the mining enterprises, creating an appropriate infrastructure, increasing the region’s investment attractiveness, developing interregional and international cooperation in the field of subsoil extracting management.

At present time, the issue of defining indicators of sustainable development corresponds to the processes of modern economy development such as digitalization, technological convergence. They are going to replace mining from GDP of industrial countries and decease environmental pressure by expanding economy of knowledge. For the first time, the knowledge index was calculated by the World Bank. It should be noted that the World Bank calculated the indices for each individual country. This would allow developing the necessary decisions and government policies to build a knowledge economy. This goal is pursued by the authors of the article, but in relation to the sustainable development of the mining regions of Russia. The article discusses various approaches to assessing the regional knowledge index, and proposes a new methodology for its assessment based on the main determinant of the matrix and its logarithm. Based on the proposed methodology, the knowledge index was evaluated, which shows the conditions for the knowledge economy development in the mining regions of Russia. The rating of the mining regions of Siberian Federal District was built. The main conditions affecting the formation of the knowledge economy in the mining regions of Siberia in the context of their sustainable development are identified.

A characteristic feature of the innovative economy is the increasing role of human capital, knowledge and high technologies. According to the indicators of innovative development, Russia lags behind the Western countries. At the same time, the development of Russian regions is extremely uneven. First of all, this applies to the mining regions. Technological parks should bridge the gaps and help the mining regions to integrate into the new economy. The authors consider the essence of techno-parks, the history of their establishment in Russia, and also analyze the dynamics of the main indicators of their functioning. When considering techno-park structures of the Tomsk and Kemerovo regions, the most important problems inherent these regions are highlighted. The authors analyze in detail the results of the innovation territorial center "ITC Tomsk" and the Kuzbass Techno-park, determine the main activities for the integration of mining regions in the innovation economy and characterize the positive effect of the techno-park structures functioning.

In the present work, a new method of growing layers of three main crystal modifications of Ga2O3, namely α-phase, ε-phase, and β-phase, with thickness of 1 µm or more was developed. The method is based on the use of two approaches, namely a combination of Ga2O3 growth using the hydride vapor-phase epitaxy (HVPE) method and the use of a silicon crystal with a buffer layer of dislocation-free silicon carbide as a substrate. As a result, Ga2O3 gallium oxide layers of three major Ga2O3 crystal modifications were grown, namely, α-phase, ε-phase, and β-phase. The substrate temperatures and precursor flux values at which it is possible to grow only α-phase, only ε-phase, or only β-phase without a mixture of these phases were established. It was found that the metastable α- and ε-phases change into the stable β-phase when heated above 900 °C. Experimentally obtained Raman and ellipsometric spectra of α-phase, ε-phase, and β-phase of Ga2O3 are presented. The theoretical study of the Raman spectra and the dependences of dielectric function on photon energy for all three phases was carried out. The vibrations of Ga2O3 atoms corresponding to the main lines of the Raman spectrum of the α-phase, ε-phase, and β-phase were simulated by density functional methods. [ABSTRACT FROM AUTHOR]

The nanolayers of single crystal SiC were grown on the surface of a high-resistance n-type silicon substrates by replacement of the atoms in the crystal lattice of silicon on the carbon atoms at the temperatures of 1250, 1330 °C and CO gas pressures 264, 395 Pa, respectively. The formation of crystalline β-SiC phase in films by electron diffraction and Raman spectroscopy techniques was shown. The SiC films are epitaxial and do not contain twins on the surface. By Atomic Force Microscopy is shown that two set of SiC films have pyramidal and step-like structure of the surface with clear-cut fragmentation of grains with sizes between 100 and 200 nm, and this is due to the composition of carbon and silicon atoms in the layer. Two set of SiC films have a granular surface structure with indistinct grain fragmentation. The influence of synthesis condition on the microstructure of film surface is discussed.

The growth of an arbitrary multicomponent non-Kossel crystal via the Burton–Cabrera–Frank mechanism is studied, considering the effect of advacancies and their recombination with adatoms on the surface. An analysis is carried out for two cases: growth due to vapours and growth due to chemical reactions. The analytical expressions are found for the rate of advancement of a group of equidistant steps and the crystal growth rate considering the properties of all the species involved in the growth process. Gallium nitride is used as an example to show that the effect is stronger at higher temperatures and in the presence of dopants that may increase the vacancy concentration. The impact of applied mechanical stress on the growth rate and mechanisms of its influence on the growth kinetics are discussed. It is demonstrated that the contribution of the vacancies to the total mass transfer depends on the type of applied stress. Tensile stresses increase the concentration of advacancies and total recombination rate, whereas compressive stresses lead to the opposite result. Some effects inherent to the multicomponent systems being considered are discussed. [ABSTRACT FROM AUTHOR]