Strelchuk V. Optical and structural-morphological properties of low-dimensional structures based on А3В5 and А2В6 semiconductors

The thesis is devoted to solving the problem of interrelations between structural-morphological and optical properties of low-dimensional structures based on А3В5 and А2В6 semiconductors. We ascertained the regularities of processes responsible for nucleation and lateral ordering the quantum dots (nanoislands) as well as quantum wires prepared using self-assembling in strained heterostructures. It is shown that the early stages of (In,Ga)As/GaAs (CdSe/ZnSe) heterostructure deposition are characterized by creation of 2D layer that contains interlayer plain nanoislands enriched with In (Cd), which is caused by abnormally intense deformation-enhanced interdiffusion and segregation of atoms in these strained heterostructures. Also, we ascertained the main regularities inherent to the influence of high gradient fields of anisotropic strains in the nanostructures on spatial ordering, improvement in size homogeneity as well as optical anisotropy of emission from quantum dots and wires. We found and studied the effects of component non-homogeneity and structural defects on radiative recombination of charge carriers, exciton-phonon interaction, phonon excitations, anti-Stokes emission in nanoislands. We studied also the influence of passivation of broken surface bonds in nanocrystals synthesized by chemical methods on their radiative recombination. In InAs/AlSb nanostructures, we reveal the effect of the interface type on the concentration, mobility of 2D electrons InAs QDs as well as intersubband LO-phonon plasmon excitations.