ХАРАКТЕРИСТИКА НАНОСТРУКТУРОВАНИХ ПЛІВОК ПРИРОДНОГО ОКСИДУ СЕЛЕНІДУ ІНДІЮ ЗА ДАНИМИ РЕНТУЕНІВСЬКОЇ ДИФРАКТОМЕТРІЇ МОДИФІКОВАНИМ МЕТОДОМ ШЕРРЕРА І МЕТОДОМ ВІЛЬЯМСОНА-ГОЛЛА.

Indium selenide belonging to the class of two-dimensional layered semiconductors is a promising material for nonlinear optical applications in the mid-infrared wavelength region as a detector and a source of THz waves; as the basis of various optoelectronic devices for the visible wavelength region (photodetectors, polarization-sensitive photodiodes, solar cells, phototransistors); as a matrix for hydrogen storage; as a substrate in planar nanotechnologies, etc. This compound is currently considered a useful middle ground between silicon and grapheme with great potential for manufacturing new-generation electronic and optoelectronic ultra-thin and ultra-fast nanodevices. That is why the question of InSe (both bulk and in the form of two-dimensional objects) stability in the air under ambient conditions becomes extremely relevant. Moreover, the results of recent theoretical and experimental studies on its stability are contradictive. This work is part of research aimed at studying the aging process of 2D layered compounds belonging to A³B6 family group and photosensitive devices based on them. It is shown that the necessary conditions for the oxidation of layered indium selenide crystals during their long-term storage under ambient conditions are the presence of an atomically smooth cleaved surface (0001) in the absence of growth defects and mechanical damage, as well as daylight illumination. As follows from the X-ray diffraction (XRD) study, the native oxide films formed on the van der Waals surface (0001) of InSe are two-phase and consist of pure indium and diselenium pentoxide Se2O5 nanocrystallites. A modified Scherrer equation and the Williamson-Hall method with the involvement of various models were used to determine the average crystallite size of both types of the compounds and the intrinsic strain from the XRD peak broadening the analysis. The average values of stress and the bulk energy density of deformation were also determined for pure indium nanocrystallites. Physical and chemical phenomena that lead to the presence of compressive stresses in both In and Se2O5 nanocrystallites and account for the fact that the film surface is formed by smaller crystallites than in the oxide volume have been analyzed. [ABSTRACT FROM AUTHOR]