In this work it is demonstrated that the deviation of the electrolyte/semiconductor system from an equilibrium state in a periodical way results in synchronization of the operation of different microscale regions. In this case the regions appear that can be identified with travelling of different phase waves in an excited medium. In this work the diverging spherical waves are discovered and investigated.

The intense narrow peaks have been observed in the electroluminescence spectra of the n-type nanoporous silicon under special conditions. The peaks are attributed to the separated nanocrystals which behave as quantum dots in a dielectric matrix.

A complete cycle of LED formation based on the direct laser writing technique has been developed. This technology allows to vary the set of investigated structures and conditions of their treatment. A few dozens of structures demonstrating visible electroluminescence have been investigated.

In this work the dynamics of behavior of the system consisting of the mixture of hydrofluoric acid and isopropanol solution in the 1:1 and 1:3 ratio in volume was studied during anodization. The arguments are presented in favour of the fact that the complex behavior of dynamical variables in the system suggests that in this system the bifurcation of transition to the limiting cycle can exist.

In this work the current-voltage characteristics are studied which were obtained under different anodization conditions corresponding to the formation of four basic types of pore morphologies. It is shown that the morphology of porous structure is determined by the working point position on the current-voltage characteristics of the system. The current-voltage characteristic is determined by the system parameters: sample doping level, electrolyte temperature, composition and concentration, and sample illumination intensity. Theoretical explanation of both current-voltage characteristic behavior and formation of basic morphology types is presented.

In the anodization process of n-type silicon a structure consisting of a nanoporous layer on top of a macroporous layer is formed. Many researchers believe that both photo(PL) and electroluminescence (EL) originate from the nanoporous layer [1 to 3]. We observed that the nanoporous layer was not homogenous and consisted of two sublayers (see Fig. 1a). It is stated that the top layer plays a key role in PL for n-type silicon while the bottom layer is responsible for EL.

Four morphology types of pore structures, that were formed with optimal values of parameters of the system consisted of silicon wafer and electrolyte mixture while changing either temperature or wavelength of initializing irradiation were discovered. The results of optical and electrophysical measurements and physical-chemical analysis are discussed. The assumption concerning possible self-similarity of morphologies of both structures: macro- and micropores is put forward. The analysis of general regularities testifies to existence of the universal fractal mechanism of pores formation process.

The time evolution of the photoluminescence intensity of porous silicon has been studied during steady-state excitation. The results reveal that cw visible-range laser light can cause, in addition to a degradation of the photoluminescence, an intensification of it. The quenching and restoration of the photoluminescence are described by three time scales, which are linked with reversible photosimulated changes in the concentration of radiationless-recombination centers.