Alternative and renewable sources of energy, such as wind and solar energy, hydro and geothermal energy, are attracting increasing attention all over the world. The growing interest in them is caused by environmental considerations, on the one hand, and the limited traditional earth resources - on the other. A special place among them is occupied by photovoltaic converters of solar energy.
Semiconductor thin films of metal chalcogenides of zinc subgroups due to their unique optical and electrical properties can be used in photovoltaic systems. Cadmium chalcogenides films have become the most widely used. But due to the large number of factors that effects on the properties of films, which in turn significantly effects on the efficiency of photoconductors on their basis, the choice of simple, affordable and cheap method of film synthesis will help to avoid many of them and simplify work while developing new, or improvement of existing solar cells on their base. Improving of photoconductivity by increasing the short-circuit current in solar cells with a CdS or CdSe buffer layer requires reducing the optical absorption of photons with energies less than 2.4 eV, which can be achieved by minimizing of cadmium sulfide and cadmium selenide films thickness to the optimal size.
In this paper, the advantages and disadvantages of the main methods which are used to synthesize thin-film semiconductor materials are considered and thoroughly analyzed. The main attention is focused on the choice of the chemical surface deposition (CSD) method due to its simplicity in technological terms, possibility of using various and available material sources for the synthesis of a wide spectrum of semiconductor thin-film materials at the temperatures up to 100 °С on the substrates of different nature, shape and size with a minimum amount of waste.
The main synthesis conditions of cadmium chalcogenides films are analyzed, and the comparative characterization of their influence on optical and morphological properties of films are given. In the description of the CSD method the chemistry of the low soluble CdS compound formation process was described and the influence of the initial cadmium-containing salt, chalcogenizers, pH value and the substrate nature on the properties of CdS and CdSe films were considered. Synthesis conditions and properties of cadmium chalcogenides films, obtained by various methods, are summarized in one table.
Therefore, the search for an optimal method for the production of film materials is one of the key stages in the process of their synthesis with the required functional properties for the development of new thin-film semiconductor materials and the improvement of already developed materials on their base.
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