Influence of external factors on the self-organization of lead and tin telluride nanostructures on the BaF_2(111) surface under conditions close to the thermodynamic equilibrium

摘要

The morphology of PbTe and SnTe nanostructures grown on BaF_2(111) substrates from the vapor phase in a vacuum under conditions close to the thermodynamic equilibrium has been investigated using atomic force microscopy. The equilibrium shape of PbTe and SnTe quantum dots and the statistical parameters of arrays of these quantum dots have been studied as a function of the thermodynamic conditions of growth, the crystal lattice mismatch between the materials of the quantum dots and substrate, and elastic properties of these materials. It has been established that, when the BaF_2(111) substrate is deformed under external mechanical loading, the self-organization of dislocations on the BaF_2(111) surface can result in the formation of a nanoscale ordered strain relief, which can be used for the fabrication of nanostructures. The morphology of this relief depends on the external load and on the temperature at which the substrate is deformed. It has been shown that the deformation effect on the surface of the substrate and light irradiation of the growth zone of nanostructures affect the nucleation of islands and kinetic processes occurring on the surface of the substrate during their growth. Using the influence of external factors on the BaF_2(111) surface under certain thermodynamic conditions, it is possible to grow SnTe and PbTe nanostructures with different morphologies: continuous epitaxial layers with a thickness of less than 10 nm, homogeneous arrays of quantum dots with a high lateral density (more than 10~11 cm~2), quasi-periodic lateral nanostructures (nanowires), "single" and "coupled" quantum dots, and "molecules" of quantum dots.