Antonin S. Electrical and optical properties of the structures with silicon nanocrystals

In today's world, electronic and optoelectronic devices play a key role in all areas of life from education and medicine to defense technology. And all this would not be possible without a thorough understanding of the processes that occur during the operation of electronic devices. Therefore, for the further development of electronics and progress in this field it is necessary to fundamentally study promising materials, structures and technologies. One of the most promising areas is the study of nanoscale objects, especially crystals of this size. Using the properties of nanocrystals, you can improve the characteristics of the structures of which they are part. To realize these possibilities, it is necessary to study nanocrystals and their properties in various matrices, including SiO2. When developing and creating new electronic devices, it is important to study the physical processes and effects that occur in them, in particular, the mechanisms of charge transport in such structures. On the other hand, there is great interest in resonant tunnel structures used in ultra-high frequency technology as generators of electrical signals (up to the terahertz range) and in field emission devices to create narrow electron beams in "nanoscience" systems. With the development of nanotechnology there is an active search for new approaches to the implementation of resonant tunnel structures. In particular, structures in which semiconductor nanocrystals act as quantum wells and amorphous films are barriers are studied. Currently, active research is also being conducted on various types of solar cell coatings to improve their efficiency. Anti-reflective coatings play a very important role, especially in improving the efficiency of solar cells. Another advantage is that the coating on the surface of the solar cell can shift the spectrum of light absorbed by it (up- and down-conversion). Films with silicon nanocrystals are promising for use as brightening coatings and for expanding the absorption band of photovoltaic converters. The aim of the dissertation is to establish the physical mechanisms of electronic transport through thin nanocomposite films SiO2(Si)&FexOy(Fe) with silicon and iron nanoinclusions, to determine the features and mechanisms of electronic field emission from resonant tunnel structures with Si nanocrystals, to establish the possibility of using composite oxide films. silicon nanocrystals to improve the performance of photovoltaic converters. During the dissertation the following scientific results were obtained: The technological process of obtaining nanocomposite oxide film with excess silicon and iron by ion-plasma spraying has been developed. Mechanisms of electronic transport through nanocomposite films SiO2(Si)&FexOy(Fe) with nanoinclusions of silicon and iron in a wide range of temperatures and electric fields are established and parameters of traps (energy position, concentration) involved in electrical conductivity are determined. Porous silicon layers were obtained by galvanic anodizing at different current densities and their surface morphology was established. Features of distribution of alloying impurity in nanowires of porous silicon by a method of volt-farad characteristics are established. The peculiarities of electron field emission in vacuum from porous silicon layers are established and a model for their explanation is proposed. Optical characteristics of nanocomposite oxide films with nanocrystals of silicon and two-layer structures SiOx(Si) / diamond-like carbon film (DLC) are determined. The influence of γ-radiation on the characteristics of two-layer structures SiOx(Si) / diamond-like carbon film to determine their radiation resistance.