INVESTIGATION OFINDIUM (III) SULFIDE THIN FILMS PROPERTIES OBTAINED BY CHEMICHAL BATH TECHIQUE

Due to its unique optical and electrical properties semiconductor metal - sulfide and metal – selenide thin films can be used in photovoltaic systems. The largest using acquired CdS films. But due to its toxicity, there is considerable interest in replacing CdS other semiconductor films with similar or even better properties obtained by chemical bath deposition (CBD). One of the promising candidates for replacing cadmium sulfide is chemically deposited film indium sulfide. In this paper were reviewed and analyzed the main aspects of synthesis indium sulphide thin films by CBD. Attention is focused on choosing a method of chemical deposition due to the simplicity of its execution in technological term, possibility of the using different initial substances for the synthesis wide range of semiconductor thin films at temperatures up to 100ºC. The basic conditions synthesis thin films were analyzed. Examined their impact on the phase composition, optical and morphological properties of the films. In3+ ions donor are the salt of indium chloride (InCl3×4H2O) or indium sulfate (In2(SO4)3), donor S2- is thioacetamide (TAA, CH3CSNH2). In all cases, stated that the experiments were carried out in a strongly acidic environment (pH = 1 - 2.5). The acidic environment created by using a solution of sulfuric acid. Acetic or citric acid added as complexing agents. The synthesis of thin films was carried out pre-prepared substrate. In the majority of synthesis methods as a substrate serves glass or it's different modificatios: Pyrex (borosilicate glass), fluorine doped tin oxide (FTO) coated glass, systems glass/SnO2, glass/Cu3BiS3, ITO/glass, in some cases - polymers. The glass substrate washed with a chromic mixture, then washed by distilled water and dried for 10-15 minutes. The temperature of the working solution in the range of 50 - 90°C. The film thickness directly proportional to the deposition time and is highly depend on the nature of the substrate and pre-processing. In studying of the structure indium sulfide thin films was fixed the presence of phase β-In2S3, after annealing the samples, on diffractograms new phase In6S7 was observed. Conditions for obtaining and properties of indium sulfide thin films in are consolidated in table. Investigations results of physical and chemical properties of the films were summed up. Highlighted optimal conditions for chemical bath deposition films of indium sulfide depending on the nature of the substrate and the method of preparation. Particular attention is paid to the analysis, comparison physical and chemical properties of films according to the synthesis conditions.