Structural and optical characteristics of Ge/Si nanolayers with spatialy ordered groups of quautum dots
Ge/Si nanostructures with closely spaced and interacting Ge quantum dots were grown by molecular beam epitaxy. It was found that the GeSi quantum rings with closely spaced Ge quantum dots can be formed by choosing suitable deposition rate and temperature of Ge. The unit cell parameters and Ge concentration in Ge/Si nanostructures were determined by the X-ray diffraction method. Intense luminescence bands caused by radiative recombination of excitons from both the Ge wetting layers and Ge quantum dots were found in photoluminescence spectra at 4.2 K.