Characterization of SnTe films grown by molecular beam epitaxy

Abstract

A series of SnTe layers with thicknesses varying from 0.42 to 9.1 µm were grown by molecular beam epitaxy on (111) BaF 2 substrates. The SnTe lattice parameter was found to be 6.331Å as determined from x-ray diffraction spectra measured in the triple-axis configuration. The FWHM of the (222) SnTe x-ray rocking curves indicated a good crystalline quality and an unusual dependence on layer thickness. Atomic force microscopy (AFM) of the SnTe surface revealed spirals with monolayer steps formed around threading dislocations, similar to the PbTe on BaF 2 epitaxy. The dislocation density was estimated from the AFM picture to be 9x10 8 cm −2 . Small black pits corresponding to holes that were left during growth were also observed on the AFM images. Sn diffusion can be a possible reason for these pits and the relatively high dislocation density. Electrical measurements showed that the SnTe epilayers present a typical p-type carrier concentration around 10 20 cm −3 almost temperature independent and a Hall mobility which decreases from 10 4 to 10 3 cm 2 /V.s as the temperature increases from 10 to 350K.

Proximity-Induced Superconductivity and Quantum Interference in Topological Crystalline Insulator SnTe Thin-Film Devices

“…The determination of the Hall coefficient with Hall measurements at 2 K (not presented) show that the charge-carrier type is strongly hole-like and the carrier density is about n ≈ 4.5·10 20 cm -3 . As SnTe is known to tend intrinsically to high carrier concentrations due to Sn vacancies (and hence to p-type behaviour), this is consistent with current reports of other researchers [19].…”

Molecular beam epitaxial growth of EuTe/SnTe strained superlattices

“…The worsening of the films grown with substrate temperatures above 310 C can be explained by the preferential desorption of Te species from the growing film surface. The minimum FWHM of 110 00 obtained for the SnTe films indicates a very high structural quality compared to previously reported values of 190 00 [11] and 161 00 [12].…”

“…Previous studies on the growth of SnTe on BaF 2 substrates have focused on dislocation densities and films crystalline quality as a function of thickness [11,12]. Here, we studied the influence of substrate temperature on the SnTe structural quality.…”

Unit cell distortion and surface morphology diversification in a SnTe/CdTe(001) topological crystalline insulator heterostructure: influence of defect azimuthal distribution

“…Thus, the mean values are comparable with the reported data. 63,68,69 The individual FWHM values for SnTe depend significantly on the layer thickness (see Fig. 2).…”