Controlling Structural Anisotropy of Anisotropic 2D Layers in Pseudo-1D/2D Material Heterojunctions

Area of Science:

• Materials Science
• Nanotechnology
• Surface Science

Background:

• Two-dimensional (2D) materials offer unique electronic and optical properties.
• Lateral heterojunctions between dissimilar 2D materials are crucial for advanced electronic devices.
• Anisotropic materials present challenges in controlled growth and interface engineering.

Purpose of the Study:

• To investigate the chemical vapor deposition and growth dynamics of 2D lateral heterojunctions between pseudo-1D ReS2 and isotropic WS2.
• To provide the first atomic-level understanding of interfaces between anisotropic ReS2 and isotropic WS2.
• To explore the control over anisotropy direction in 2D materials for nanomanufacturing.

Main Methods:

• High-resolution scanning transmission electron microscopy (HR-STEM)
• Electron energy loss spectroscopy (EELS)
• Angle-resolved Raman spectroscopy

Main Results:

• First atomic resolution of ReS2/WS2 lateral heterojunctions.
• Discovery of well-oriented Re-chains perpendicular to WS2 edges.
• Anisotropy control depends on domain size, with larger domains leading to reduced anisotropy due to Re-chain randomization.

Conclusions:

• Established growth dynamics for atomic junctions between anisotropic and isotropic 2D materials.
• Demonstrated control over anisotropy direction in 2D material heterojunctions.
• Significant advancement for large-scale nanomanufacturing of anisotropic systems.