Sychikova Y. Scientific and methodological basis of assessment the quality and properties of nanostructures on the surface of semiconductors

3. An urgent problem of developing the systems of evaluating the quality of nanostructures formed on the surface of semiconductors has been solved in the dissertation. A generalized model for synthesis of nanostructures with a preset level of quality on the surface of semiconductors based on the principles of process and systems approaches is created. Based on the developed model, the decomposition of the process "synthesizing nanostructures of a specified quality level" is carried out. The model for synthesis of nanostructures, on the basis of which the nomenclature of quality indicators of nanostructures has been determined, is developed. Based on the experimental research, the work presents that resource and processing factors and the parameters of the output crystal influence on the quality of nanostructures synthesized on the surface of semiconductors. With the help of the analysis technique of hierarchies, it is established that electrochemical etching is the most optimal method for synthesizing nanostructures on the surface of semiconductors. The technique of upgrading the quality and stabilizing the properties of nanostructures is improved by using surface passivation method for nanostructures that leads to the chemical inertness and electric inertia of nanomaterial. The main morphological quality ratings of nanostructures that are formed on the surface of semiconductors are identified. They are: diameter, density, form factor of nanocrystallites and thickness of a nanostructured layer. The main chemical quality ratings of nanostructures are determined. They are: the stoichiometry, the homogeneity of the allocation of elements on the surface, the availability of oxide layers and the chemical stability of synthesized nanostructures. The correlation between technological factors of synthesis of porous space on the surface of semiconductors and acquired chemical and morphological characteristics is investigated. It is shown that current density of the anodizing, the time of etching, the parameters of the output crystal, the composition and electrolyte concentration affect the quality of nanostructures. A generalized quality criterion of nanostructures that is presented as the functions of the partial criteria is developed. The generalized criterion is universal. It allows estimating the quality of different types of nanostructures on the surface of semiconductors. The technique of estimation of nanomaterials by the degree of potential hazard is developed in order to establish regulations on safety issues of nanotechnological products. The estimation of conformity of synthesized porous layers to the functionality for using as a material of photoelectric energy converters and supercapacitors is carried out.