X-ray mapping in a scanning transmission electron microscope of InGaAs quantum dots with embedded fractional monolayers of aluminium

We investigate AlGaAs/GaAs superlattices as well as InGaAs/GaAs quantum wells (QWs) and epitaxial quantum dots (QDs) where during the molecular beam epitaxy of InGaAs QDs the aluminium flux cell was opened briefly to incorporate fractional monolayers of Al into the InGaAs. We show that X-ray mapping with a large collection angle is capable to detect 0.3-0.4 fractional Al monolayers with a resolution of just under 1nm

Structural changes in multilayer systems containing InxGa₁₋xAs₁₋yNy quantum wells

The investigations of multilayer nano-scale systems contained one or two quantum wells are carried out by double-crystal X-ray diffractometry. Processes of interdiffusion of In, Ga atoms and their influence on properties of such systems are considered. The content of nitrogen in quantum wells and buffer layers are defined. It is determined that InxGa₁₋xAs₁₋yNy system has perfect crystalline structure, and interface between layers is coherent