Igor Kolupaev

The authors study the nonuniformity of a-Si:H films obtained by the method of vacuum condensation, with the help of x-ray small-angle scattering (SLS) and transmission electron microscopy. Films of hydrogenated amorphous silicon are greatest interest, because the electronic properties of this material can be controlled by doping. As a result of the compensation of the ruptured bonds, and possibly, effects of melting, the properties of such films are analogous to those of singlecrystalline silicon. XLS enables a quantitative determination of the prameters of the regions of low electron density (RLD) in such objects.

Methods of X-ray diffraction and transmission electron microscopy were used to study the microstructure of dispersion-strengthened Cu-Al2O3 nanocomposites obtained by the method of simultaneous deposition of Cu and Al2O3 from the vapor phase. The effect of the size of particles of the oxide (Al2O3) and of their content on the electrical resistance of the composite has been considered. The results obtained make it possible to suppose that the main structural factor that determines the electrical resistance of the composite are nanodispersed particles of Al2O3 with a size of less than 20 nm.

In the CVD method, samples of carbon condensates were obtained under special conditions (low substrate temperature and short growth times). The use of special technological conditions makes it possible to study the initial stages of growth of graphene layers. To analyze the influence of the microinhomogeneities of the copper substrate on growth conditions, various modes of its electrochemical polishing were used in the study. The structural state of the surface was studied using computer processing of digital images of a surface with color segmentation. A metallographic analysis of more than 70 samples was carried out and three main structural elements of the initial stage of growth of graphene layers were identified on the basis of computer image processing during condensation. These are graphene layers, sections of a copper substrate and a cluster of atoms with a structural state different from the graphene (presumably amorphous). It has been established that preparation of the su...

Samples of polygraphene layers on a copper substrate were obtained using CVD technology. For the preparation, a gaseous mixture of methane, hydrogen and argon was used. To analyze the degree of filling and the specific area of the polygraphene formed on a copper substrate, we used optical microscopy (with specialized computer image processing) in combination with Raman spectroscopy and atomic force microscopy. It is proposed to use the approach based on the double structure model (transparent regions of graphene and copper) for evaluating the morphological parameters of the coating of polygraphene on a copper substrate. This approach is used for the primary optimization of the production process of polygraphene formation. The mechanism of initial stages of polygraphene growth on copper is proposed.