Moiré Pattern Formation in Epitaxial Growth on a Covalent Substrate: Sb on InSb(111)A

Abstract

Structural moirésuperstructures arising from two competing lattices may lead to unexpected electronic behavior. Sb is predicted to show thickness-dependent topological properties, providing potential applications for low-energy-consuming electronic devices. Here we successfully synthesize ultrathin Sb films on semi-insulating InSb(111)A. Despite the covalent nature of the substrate, which has dangling bonds on the surface, we prove by scanning transmission electron microscopy that the first layer of Sb atoms grows in an unstrained manner. Rather than compensating for the lattice mismatch of −6.4% by structural modifications, the Sb films form a pronounced moirépattern as we evidence by scanning tunneling microscopy. Our model calculations assign the moirépattern to a periodic surface corrugation. In agreement with theoretical predictions, irrespective of the moirémodulation, the topological surface state known on a thick Sb film is experimentally confirmed to persist down to small film thicknesses, and the Dirac point shifts toward lower binding energies with a decrease in Sb thickness.

Moiré superlattices of antimonene on a Bi(111) substrate with van Hove singularity and Rashba-type spin polarization

“…1c, d shows that the surface is divided into three characteristic regions in terms of topographic height. By comparing these observations to previous reports on related moiré superstructures [47][48][49][50][51] , we can safely assign them to the regions of the AA, AB, and AC stacking sequences (Fig. 1e).…”

Emergence of quasi-1D spin-polarized states in ultrathin Bi films on InAs(111)A for spintronics applications

“…In contrast to silicon and germanium, III–V semiconductors are quite promising for a large number of electronic and optical applications because they have a direct band gap and high charge carrier mobility, providing great flexibility in the integration of different materials. 31–33 It was recently discovered that GaAs(111)-B facilitates the formation of a honeycomb bismuthene holding topological spin-polarised states, 34 while InAs(111)A and B substrates were found to promote the growth of Bi crystalline films of 2 ML and 12 ML thickness. 35 A Bi film of ∼30 ML thickness has been successfully grown on the InAs(111)A and B sides, forming a high-quality Bi monocrystal.…”