Structural characterization of Pb$_{0.7}$Sn$_{0.3}$Te crystalline topological insulator thin films grown on Si(111)

In this work, the selection and optimization of technological growth parameters of thin Pb$_{0.7}$Sn$_{0.3}$Te layers up to 300 nm thick, grown on the Si(111) surface at temperatures of 230–400$^\circ$C by the method of molecular beam epitaxy was carried out. The surface morphology of the films was studied, and the epitaxial relations were determined. It was shown that, depending on the growth temperature, the surface morphology ranges from relatively narrow terraces to smooth micrometer-sized islands with monoatomic steps on their surface.