SiGe quantum rings on the Si(100) surface

Results of experimental studies of forming SiGe nanometer-size rings on the Si(100) surface by the molecular-beam epitaxy method are presented. Detailed shapes and size distributions of the grown nanorings are studied by the atomic-force microscopy method. The elemental composition is determined by the Raman scattering method. The average germanium content in the nanorings was 37% for a forming temperature of 680°C. The obtained data on the geometry and composition of the produced nanostructures were used for calculations by the 6-band k × p-method of the energy spectrum and charge density distribution of hole states, localized on the SiGe quantum rings embedded in the Si-matrix. It is shown that the heterostructures with quantum SiGe rings are promising objects for creating devices that are capable of detecting electromagnetic radiation in terahertz and infrared wavelength ranges.