Vertical and in-plane heterostructures from WS2/MoS2 monolayers.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Engineering two-dimensional heteromaterials through layer stacking or lateral interfacing offers significant opportunities.
• Achieving atomically clean and sharp interfaces in artificial heterostructures remains a fabrication challenge.

Purpose of the Study:

• To report a novel one-step growth strategy for fabricating high-quality WS2/MoS2 heterostructures.
• To demonstrate control over the growth process for creating both vertically stacked and in-plane interconnected structures.

Main Methods:

• Utilizing a one-step vapor growth strategy.
• Controlling the growth temperature to influence heterostructure formation (high temperature for vertical stacking, low temperature for in-plane interconnection).
• Characterizing the resulting heterostructures for interface quality and electronic/optical properties.

Main Results:

• High-quality vertically stacked WS2/MoS2 bilayers with preferred stacking order and strong interlayer excitonic transitions were formed at high temperatures.
• Seamless, atomically sharp in-plane WS2/MoS2 heterostructures were achieved via lateral epitaxy at low temperatures.
• In-plane structures exhibited enhanced photoluminescence and intrinsic p-n junctions.

Conclusions:

• The developed one-step growth method is scalable and effective for creating diverse WS2/MoS2 heterostructures.
• The ability to control interface type (vertical vs. in-plane) opens avenues for novel 2D material applications.
• This approach facilitates the creation of advanced 2D materials with unique electronic and optical properties.