Influence of magnetron sputtering modes on the parameters of ZnO:Ga films

The aim of this work is to study the effect of magnetron sputtering modes - its technological parameters (pressure, substrate temperature and DC power source) on the morphology and electrophysical parameters of nanocrystalline ZnO:Ga films, which can be used as contact layers to nanostructures of photovoltaic converters. It was found that with an increase in the substrate temperature, the grain size decreases from 80 to 30 nm and the film surface roughness, as well as the resistivity from 1.68⋅10−1 to 1.2⋅10−2 Ω⋅cm and the mobility of charge carriers with 18.12 to 5.59 cm2/(V⋅s). In this case, the concentration of charge carriers increases from 5.59⋅1018 to 3.31 ⋅ 1020 cm−3. With an increase in the power of the DC source, the grain size increases from 35 to 90 nm and the surface roughness of the ZnO:Ga films, as well as the concentration of charge carriers from 5.91⋅1018 to 3.35⋅1020 cm−3. In this case, the resistivity decreases from 1.42⋅10−2 to 1.3⋅10−2 Ω⋅cm, and the mobility of charge carriers from 6.74 to 3.22 cm2/(V⋅s). The results obtained can be used in the development of technological processes for the manufacture of highly efficient photoelectric converters.

Влияние параметров кристаллической подложки на максимальную мощность кремниевых гетеропереходных солнечных элементов

The effect of the donor impurity concentration and the lifetime of charge carriers in a crystalline silicon substrate on the maximum power of heterojunction thin-film solar cells is studied. The model used in the calculations takes into account the features of photocurrent generation under conditions of medium or high levels of injection of charge carriers at an arbitrary ratio between the diffusion length and the thickness of the semiconductor wafer. The proposed technique makes it possible, with sufficient accuracy for practical purposes, to calculate the permissible variation limits of the substrate parameters, which ensure the specified values of the performance characteristics of photoelectric converters.

Фотоэлектрические преобразователи узкополосного излучения на основе гетероструктур InGaAsP/InP

Utilizing performed research, photoelectric converters of narrow-band radiation (λ ≈ 1.0–1.3 µm) based on InGaAsP / InP heterostructures with an epitaxial p / n junction have been developed and created. Technological regimes that apply of for creating high-quality layers of quaternary InGaAsP solid solutions isoperiodic to indium phosphide in a wide range of compositions by liquid-phase epitaxy have been determined.

ENERGY FLOW CONTROL IN COMBINED POWER SUPPLY SYSTEMS FOR AGRICULTURAL FACILITIES

The article proves the practicality of transferring individual objects of the agro-industrial sector to a combined power supply using a centralized network, photoelectric converters, and batteries. The authors state that there is no available information about the functioning algorithm of the combined power supply systems from foreign manufacturers and prove the necessity of independently developing and popularizing such systems. The article provides movement directions of energy fl ows in combined power supply systems. These areas off er the mutual redistribution of electrical energy between photovoltaic converters, batteries, consumers, and the industrial network. The authors show the prospects of developing the commercial supply of autonomously generated surplus electricity to the grid. The conditions for implementing the main directions of energy fl ows are formulated, and an algorithm for controlling the system elements is drawn up. The article presents the design of a basic relay-contact electrical circuit of the command-switching device of the combined power supply system. The authors describe the design of a semiconductor inverter ensuring the in-phase of the generated voltage with the industrial network voltage and present the block diagram of a command-switching device based on logical elements.

Theoretical and Methodological Calculations of Solar Energy Resource Potentials in the Northern Garagum

The urgency of the issue is the development of the Garagum desert, which occupies 80% of the land resources of Turkmenistan. The aim of the research is to supply the desert regions of the Garagum with energy using solar energy technologies and installations. The research task - to determine the solar-energy resource potential using innovative methods of calculation in the design, creation and implementation of efficient solar energy technology and equipment. Methodology. To determine the gross, technical, economic and ecological potential, the natural and climatic conditions of the Northern Garagum are taken into consideration. Research methodology - used meteorological data, processed by laws of physics and mathematical calculation methods for thermal and photoelectric converters. Research results. The theoretical and methodological calculations of the gross, technical, economic and environmental potentials of solar energy are estimated, the energy efficiency of solar radiation is determined, and the optimal solar collector inclination angles for the Northern Garagum are calculated. Discussion and conclusion. As a result of the research, the resource potentials of solar energy were obtained, converted into thermal and electrical energy, kW•h/m2 per year: gross - 1844.6; technical - 1227.58 and 244.85; economic - 1354.58 and 270.25. Environmental potentials, CO2, kg / year: 784.96 and 156.6. The most effective for the use of solar collectors in the Northern Garagum for months of the year with an angle of inclination is: 60 degrees - January, February, November, December; 45° - March, October; 30° - from April to September.

Problems of irradiance characteristics measurement of solar simulators for ground spacecraft tests

The reliability of both spacecraft as a whole and of their systems is confirmed at the stage of complex ground-based experimental tests, including complex thermal vacuum tests. The thermal state of the test object in thermal vacuum chambers is obtaining, in particular, using a solar simulator. Radiometers based on silicon photoelectric converters are most often used to control the irradiance of a solar simulator under conditions of thermal vacuum tests. At the same time, an analysis of the features of silicon photoelectric converters shows that their direct measurement with the accuracy required for ground-based tests of spacecraft is impossible; their output is nonlinear, depends on the received spectrum, their own temperature and has long-term instability. The achieved measurement accuracy directly depends on the number and accuracy of the tools used and the methods of the necessary correction, of which the mismatch correction between the solar simulator spectrum and the solar spectrum is the most difficult and laborious. At the same time, spectrally nonselective heat flux radiometers are free from the above disadvantages. In the course of the experiment we carried out, the significant dependence of the accuracy of measuring the irradiance with radiometers based on silicon photoelectric converters on the received spectrum was confirmed. The conclusion is made that direct measurement by heat flux radiometers of the irradiance of the solar simulator is most justified under the conditions of thermal vacuum tests.

PEROVSKITE PHOTOELECTRIC CONVERTERS WITHOUT HOLE-CONDUCTING BUFFER LAYERS

The review article is devoted to research in the field of the formation of photoelectric converters based on organic-inorganic perovskites without hole-conducting buffer layers using carbon materials as the back contact.

INVESTIGATION OF PHOTOELECTRIC CONVERTERS WITH A BASE CADMIUM TELLURIDE LAYER WITH A DECREASE IN ITS THICKNESS FOR TANDEM AND TWO-SIDED SENSITIVE INSTRUMENT STRUCTURES

Photovoltaic cells with a base layer of cadmium telluride with a decrease in its thickness are studied. It is known that the widespread use of photovoltaic converters is constrained by their high price in the case of highly efficient instrument structures, or low efficiency. The creation of tandem and two-sided sensitive photoelectric converters will reduce their cost while increasing their efficiency. However, to create tandem and two-sided sensitive photoelectric converters, the necessary conditions are the use of transparent contacts and a decrease in the thickness of the base layer for efficient absorption of incident radiation by the converter, which is lower. In the research process, it was found that reducing the thickness of the base layer to 1 μm allows to increase the efficiency of the photoelectric transducer during irradiation from the back. An increase in the efficiency of the photoelectric converter occurs due to a decrease in the distance from the generation region of nonequilibrium charge carriers in the region of separation. If the thickness of the base layer is less than 1 μm, then regardless of which side of the irradiation is carried out, a decrease in the efficiency of the instrument structure is observed. Increase in the efficiency of photoconverters is associated with an increase in the negative influence of recombination processes on the back contact, a decrease in the number of charge carriers generated due to incomplete absorption of incident radiation, and a decrease in the volume of the built-in field of the separating barrier when it overlaps with the depletion region of the back contact. ITO/CdS/CdTe/Cu/ITO SCs with a base layer thickness of 1 μm demonstrates degradation stability. The highest value of efficiency in the case of illumination from the front side 8.1 % and with illumination from the back side 3.8 % received after a year of operation of the photovoltaic converter.