Structural and optical properties of two-dimensional Si and Ge layers formed by molecular beam epitaxy on CaF-=SUB=-2-=/SUB=-/Si(111) substrates

Approaches to the formation of epitaxial structures containing two-dimensional Si and Ge layers embedded in a CaF2 dielectric matrix have been developed. Raman study demonstrates the presence of narrow peaks related to Si-Si- and Ge-Ge-bond vibrations in the growth plane of structure. In the photoluminescence spectra of the created structures, emission bands, which can be associated with the radiative recombination of charge carriers in two-dimensional Si and Ge layers embedded in CaF2 have been found. Keywords: silicon, germanium, two dimensional, calcium fluoride, molecular beam epitaxy, electron irradiation, atomic structure, photoluminescence.