Lateral heterojunctions within monolayer MoSe2-WSe2 semiconductors

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Heterojunctions in 3D semiconductors are crucial for modern electronic devices like LEDs and transistors.
• Developing analogous heterojunctions in 2D materials is key for advanced band engineering and novel device architectures.
• Current methods for creating 2D heterostructures often face challenges in achieving seamless, high-quality interfaces.

Discussion:

• This study demonstrates the successful growth of seamless, high-quality in-plane heterojunctions between molybdenum diselenide (MoSe2) and tungsten diselenide (WSe2) monolayer semiconductors.
• The lateral heteroepitaxy technique using physical vapor transport yields junctions that are optically visible and exhibit enhanced photoluminescence.
• Atomically resolved transmission electron microscopy confirms an undistorted honeycomb lattice structure with clean interfacial transition metal substitution.

Key Insights:

• Achieved seamless, high-quality in-plane heterojunctions between distinct 2D monolayer semiconductors (MoSe2 and WSe2).
• Demonstrated a viable growth method (lateral heteroepitaxy) for creating these 2D lateral junctions.
• Verified the atomic structure and interface quality using advanced microscopy techniques.

Outlook:

• The development of in-plane 2D heterojunctions opens new avenues for creating novel electronic and optoelectronic devices.
• This work paves the way for integrating in-plane transistors and diodes within a single atomically thin layer.
• Future research can explore band engineering possibilities and device applications leveraging these unique 2D lateral structures.