Introduction. Heterojunction silicon solar cells represent one of the most promising directions for the development of solar photovoltaics. This is due to both their high power conversion efficiency and reasonable likelihood for further growth in performance, as well as good commercial potential of this technology, which relies on a transition from conventional diffusion-based processes to thin film deposition. Aim. The paper describes results of optimization and fabrication of heterojunction silicon solar cells using the AK-1000 inline tool, adapted for processing of 6-inch wafers. Materials and methods. In the manufacturing of solar cells, crystalline silicon wafers were subjected to wet chemical processes, and then electron, hole, and intrinsic types of conductivity of the layers based on amorphous silicon were deposited by plasma-chemical deposition. Precipitation of oxide transparent conductive layers was carried out by magnetron sputtering. To optimize the processes of obtaining solar cells, measurements of the reflection coefficient, of lifetime of minority carriers, and of current-voltage characteristics were used. Results. As a result of the work, heterojunction solar cells were obtained in a laboratory in Kazakhstan with an efficiency of 20% without using of traditional diffusion processes for solar cells manufacturing. Conclusions. The output parameters associated with light conversion efficiency demonstrate the possibility of further optimization of the parameters affecting the performance of heterojunction solar cells.

Mathematical simulation of temperature distribution on double-sided solar cells has been carried out. Differences in the configuration of photoelectric converters prove to solely amount to the fact that a double-sided solar cell has a more efficient heat sink at the rear side. Furthermore double-sided solar cells exhibit higher power conversion performance. Calculations confirm the correctness of giving preference to double-sided solar cells which is of great importance for the photoelectric converter design developed by us. Analysis of market-available photovoltaic technologies of solar energy to electric power conversion has led to the development of a photovoltaic converter on the basis of double-sided silicon heterojunction solar cells. The configuration developed is a moving platform having a photovoltaic cell array mounted on it and a light flux collector. A double-axis tracking system has been developed for the general case of planar attachment of solar cell modules. A 350 mm stroke drive provides for movement in the north-south direction and a 450 mm stroke drive, in the east-west direction. The task has been outlined to find the required arm for providing symmetrical positioning at the maximum rotation angle about the axis. As a result, technical solutions have been developed for the north-south and the east-west directions. Furthermore a schematic wiring diagram has been designed to implement the preset solar tracking system algorithm. The system is also fitted with a GPS/GLONASS module for system precision positioning and time synchronization.

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The influence of charge components on emergence of a homogeneous phase of silicon in the process of silicon dioxide reduction by aluminium has been studied. Optimal process parameters affecting the quality of the end product have been identified. These include the ratio of components of the synthetic charge (CaO, SiO 2 , CaF 2), the optimal amount of SiO 2 , the optimal amount of a reducing agent (Al) and the optimal Si/slag ratio. The homogeneous phase of silicon is easily separated from the slag, which contributes to the reduction of waste silicon during further technological operations.