Diadenchuk A. Heterostructures based on porous semiconductors (Si, A2B6 and A3B5)

The thesis is devoted to the study of the physic-technological conditions for growing low-dimensional structures on the porous surfaces of semiconductors (Si, A2B6, A3B5) and to study their properties for expanding the understanding of the nature of processes in semiconductor heterostructures, which will find wide application in the manufacture of new modern opto- and microelectronics devices, nanophotonics, etc. SiC films were obtained for the first time on the macro- and mesoporous Si surfaces of various orientations by chemical substitution of the atoms. The growth mechanisms of silicon carbide (SiC) films by the substitution of atoms on meso- and macroporous silicon (Si) substrates of p- and n-type conductivity orientations (100) and (111) are investigated. Radiation-beam epitaxy was used to fabricate heterostructures that are oxide coatings of ZnO and In2O3 on the porous surface of ZnSe and InP. Zinc oxide nanotubes (~ 10 microns in height, the outer diameter of the tubes vary from 0.5 to 2 ?m) on the ZnSe substrate and embedded indium oxide nanotubes on the surface of the porous InP are obtained. The growth mechanisms of ZnO/porous-ZnSe/ZnSe and In2O3/porous-InP/InP semiconductor heterostructures are investigated. A heterostructure GaN/porous-GaAs/GaAs was fabricated, and a model of the growth of GaN quantum dots as a result of the treatment of porous GaAs by excited nitrogen atoms was considered. According to experimental and theoretical calculations, the size of GaN quantum dots is about 20-30 nm. A technology has been developed for obtaining a heterostructure CdS/porous-Si/Si by chemical surface deposition of thin CdS films on the surface of a porous-Si crystal. The thickness of the CdS layer is uniform and varies from 100 to 120 nm, studies prove the uniform distribution of S and Cd over the entire thickness of the film. The ZnO:Al/porous-CdTe/CdTe heterostructure was fabricated and investigated. X-ray diffractometry studies of the structure and phase composition of the electrodeposited zinc oxide layers revealed that all the diffraction peaks, with the exception of those related to the porous-CdTe substrate, correspond to the hexagonal modification of the ZnO wurtzite type.