Designing Artificial Two-Dimensional Landscapes via Room-Temperature Atomic-Layer Substitution

Abstract

Manipulating materials with atomic-scale precision is essential for the development of next-generation material design toolbox. Tremendous efforts have been made to advance the compositional, structural, and spatial accuracy of material deposition and patterning. The family of 2D materials provides an ideal platform to realize atomic-level material architectures. The wide and rich physics of these materials have led to fabrication of heterostructures, superlattices, and twisted structures with breakthrough discoveries and applications. Here, we report a novel atomic-scale material design tool that selectively breaks and forms chemical bonds of 2D materials at room temperature, called atomic-layer substitution (ALS), through which we can substitute the top layer chalcogen atoms within the 3-atom-thick transition-metal dichalcogenides using arbitrary patterns. Flipping the layer via transfer allows us to perform the same procedure on the other side, yielding programmable in-plane multi-heterostructures with different out-of-plane crystal symmetry and electric polarization. First-principle calculations elucidate how the ALS process is overall exothermic in energy and only has a small reaction barrier, facilitating the reaction to occur at room temperature. Optical characterizations confirm the fidelity of this design approach, while TEM shows the direct evidence of Janus structure and suggests the atomic transition at the interface of designed heterostructure. Finally, transport and Kelvin probe measurements on MoXY (X,Y=S,Se; X and Y corresponding to the bottom and top layers) lateral multi-heterostructures reveal the surface potential and dipole orientation of each region, and the barrier height between them. Our approach for designing artificial 2D landscape down to a single layer of atoms can lead to unique electronic, photonic and mechanical properties previously not found in nature.

References in corpus (4)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• 2D materials and van der Waals heterostructures
• Two-dimensional transition metal dichalcogenides under electron irradiation: defect production and doping
• Sequential Edge-Epitaxy in 2D Lateral Heterostructures

Cited by in corpus (8)

• Spectroscopic Signatures of Interlayer Coupling in Janus MoSSe/MoS2 Heterostructures
• One pot chemical vapor deposition of high optical quality large area monolayer Janus transition metal dichalcogenides
• Intrinsic Nonlinear Planar Hall Effect
• Nonlinear Dispersion Relation and Out-of-Plane Second Harmonic Generation in MoSSe and WSSe Janus Monolayers
• Multiple Topological Magnetism in van der Waals Heterostructure of MnTe2/ZrS2
• Photo-magnetization in two-dimensional sliding ferroelectrics
• Atomically-precise synthesis and simultaneous integration of 2D transition metal dichalcogenides enabled by nano-confinement
• Topological insulating phase arising in transition metal dichalcogenide alloy