Strain Effects in Twisted Spiral Antimonene

Abstract

Van der Waals (vdW) layered materials exhibit fruitful novel physical properties. The energy band of such materials depends strongly on their structures, and a tremendous variation in their physical properties can be deduced from a tiny change in inter‐layer spacing, twist angle, or in‐plane strain. In this work, a kind of vdW layered material of spiral antimonene is constructed, and the strain effects in the material are studied. The spiral antimonene is grown on a germanium (Ge) substrate and is induced by a helical dislocation penetrating through few atomic‐layers of antimonene (β‐phase). The as‐grown spiral is intrinsically strained, and the lattice distortion is found to be pinned around the dislocation. Both spontaneous inter‐layer twist and in‐plane anisotropic strain are observed in scanning tunneling microscope (STM) measurements. The strain in the spiral antimonene can be significantly modified by STM tip interaction, leading to a variation in the surface electronic density of states (DOS) and a large modification in the work function of up to a few hundreds of millielectron‐volts (meV). Those strain effects are expected to have potential applications in building up novel piezoelectric devices.

Rapid deposition of two-dimensional antimonene films by thermal evaporation

“…With the extension of heating time, the thermally evaporated Sb may exhibit spiral trapezoidal stacking on WS 2 causing localized inhomogeneous coverage due to spontaneous lattice distortions and in-plane anisotropic strains during the growth process. 6 Similar to previous reports, the deposition of Sb on WS 2 is directional. 27 With the continuous increase of heating time, the triangular Sb deposited on WS 2 not only gradually covers the whole WS 2 in the horizontal stitching, but also increases in the vertical thickness.…”

“…5 In addition, the unique helical growth pattern of antimony under strain-induced formation makes it greatly valuable in the study of strain effects associated with lattice dislocations, which is expected to lead to the development of new piezoelectric devices. 6…”

Epitaxy of Antimonene Thin Films with Screw Dislocations for the Application of Saturable Absorbers

“…The line-scan profile (Figure b) reveals an interlayer spacing of ∼0.45 nm, corresponding to a monolayer height of β-Sb. Indeed, a variety of materials, e.g., Sb, Sb 2 Te 3 , MoSe 2 , and WS 2 , have reported the formation of similar screw dislocation structures in epitaxial growth. Obviously, no moiré pattern exists in the dual-helical β-Sb island.…”

“…R hombohedral antimonene, synonymously called β-Sb, has garnered extensive interest thanks to its intriguing electronic features, e.g., strain-induced tunable bandgap, 1 topological edge state, 2 and piezoelectric effect. 3 For instance, it was reported that the bandgap of β-Sb can be tuned in the range of 0.11−0.21 eV by applying compressive/tensile strain. 1 Zhu and co-workers verified the existence of robust topological edge states against geometric imperfections of monolayer β-Sb.…”

“…Zhu and co-workers verified the existence of robust topological edge states against geometric imperfections of monolayer β-Sb . Recently, Huang et al demonstrated that the local density of states (LDOS) and work function of β-Sb with screw dislocations can be modulated by the voltage pulses applied through the scanning tunneling microscopy (STM) tip . The above fancy properties of β-Sb are expected to bring scientific breakthroughs to optical devices.…”