Dislocation-driven growth of two-dimensional lateral quantum-well superlattices

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) materials and heterostructures are crucial for novel electronic applications.
• Existing growth methods for 2D lateral multiheterojunctions and superlattices yield features >100 nm with rough interfaces.
• Sub-5-nm widths for quantum confinement effects and quantum-well applications remain unachieved.

Purpose of the Study:

• To demonstrate the growth of sub-2-nm quantum-well arrays in semiconductor monolayers.
• To investigate the mechanism driving the formation of nanoscale quantum wells.
• To explore the potential of these structures for future 2D integrated circuits.

Main Methods:

• Growth of sub-2-nm quantum-well arrays in lattice-mismatched sulfide/selenide heterointerfaces.
• Utilizing misfit dislocations as a driving force for controlled growth.
• Employing density functional theory (DFT) for atom-by-atom mechanism description.

Main Results:

• Successfully grew quantum-well arrays with widths below 2 nm.
• DFT calculations elucidated the atom-by-atom growth mechanism driven by misfit dislocations.
• Calculated energy bands show type II alignment, suitable for quantum wells.

Conclusions:

• Misfit dislocation-driven growth enables precise control over nanoscale widths in 2D quantum wells.
• The demonstrated structure is suitable for quantum wells and could be engineered into conductive nanoribbons for 2D integrated circuits.
• This method is applicable to various 2D monolayer combinations with lattice mismatch, opening avenues for diverse 2D quantum-well superlattices.