Coplanar semiconductor-metal circuitry defined on few-layer MoTe₂ via polymorphic heteroepitaxy.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Crystal polymorphism in transition-metal dichalcogenides (TMDCs) dictates their electronic properties, enabling metallic or semiconducting phases.
• Integrating these distinct phases is crucial for advancing two-dimensional (2D) electronic circuitry.

Purpose of the Study:

• To develop a selective and sequential vapor-phase growth strategy for integrating distinct TMDC polymorphs.
• To demonstrate the fabrication of atomically coherent polymorphic heterostructures with tunable electronic properties.

Main Methods:

• Heteroepitaxy was employed for the polymorphic integration of metallic (1T') and semiconducting (2H) MoTe2 crystals within the same atomic planes.
• Characterization of the resulting atomically coherent coplanar contacts and their barrier potentials.

Main Results:

• Successfully integrated distinct metallic (1T') and semiconducting (2H) MoTe2 polymorphs within the same atomic planes.
• Achieved atomically coherent polymorphic coplanar contacts with spatially tight-confined barrier potentials (lowest height ~25 meV).
• Demonstrated the general applicability of the synthetic approach for large-area TMDC polymorph films.

Conclusions:

• The developed heteroepitaxy method enables precise polymorphic integration of TMDCs, paving the way for advanced 2D electronic devices.
• Atomically coherent interfaces with low contact barriers are achievable, crucial for efficient charge transport in nanoscale circuits.
• This approach offers a versatile platform for engineering the electronic properties of TMDCs for future electronic applications.