Epitaxy of Layered Orthorhombic SnS–SnS_xSe_(1−x) Core–Shell Heterostructures with Anisotropic Photoresponse

Abstract

Vertical and in‐plane heterostructures based on van der Waals (vdW) crystals have drawn rapidly increasing attention owning to the extraordinary properties and significant application potential. However, current heterostructures are mainly limited to vdW crystals with a symmetrical hexagonal lattice, and the heterostructures made by asymmetric vdW crystals are rarely investigated at the moment. In this contribution, it is reported for the first time the synthesis of layered orthorhombic SnS–SnSxSe(1−x) core–shell heterostructures with well‐defined geometry via a two‐step thermal evaporation method. Structural characterization reveals that the heterostructures of SnS–SnSxSe(1−x) are in‐plane interconnected and vertically stacked, constructed by SnSxSe(1−x) shell heteroepitaxially growing on/around the pre‐synthesized SnS flake with an epitaxial relationship of (303)SnS//(033)SnSxSe(1−x), [010]SnS//[100]SnSxSe(1−x). On the basis of detailed morphology, structure and composition characterizations, a growth mechanism involving heteroepitaxial growth, atomic diffusion, as well as thermal thinning is proposed to illustrate the formation process of the heterostructures. In addition, a strong polarization‐dependent photoresponse is found on the device fabricated using the as‐prepared SnS−SnSxSe(1−x) core–shell heterostructure, enabling the potential use of the heterostructures as functional components for optoelectronic devices featured with anisotropy.

A Plasma‐Triggered O−S Bond and P−N Junction Near the Surface of a SnS2 Nanosheet Array to Enable Efficient Solar Water Oxidation

“…A sharp Raman peak at 312 cm −1 is observed for both SnS 2 and SnS 2 ‐P, which represents the typical Raman active A 1g mode of SnS 2 . Besides, an additional peak at 221 cm −1 is identified as A g vibrational mode of SnS for SnS 2 ‐P . The above results demonstrate that Ar plasma treatment (top plate with 60 W and bottom plate with 70 W) yields a mixed phase of SnS and SnS 2 .…”

Wrap‐Around Core–Shell Heterostructures of Layered Crystals

“…In addition, unique properties may arise due to curvature or strain in the shell. Such core–shell structures are distinct from SnS–SnS x Se (1− x ) lateral/vertical heterostructures with only partial shell coverage and ordinary parallel vdW layering …”

Large-size and high performance visible-light photodetectors based on two-dimensional hybrid materials SnS/RGO

“…A higher power intensity and higher voltage can drive photon-generated charge carriers to reach the electrodes faster, suppressing recombination of holeelectron pairs. 21,27 This phenomenon suggests that the photocurrent is mainly determined by the amount of photongenerated carriers under illumination.…”