Multilayer In-Plane Heterostructures Based on Transition Metal Dichalcogenides for Advanced Electronics

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• In-plane heterostructures of transition metal dichalcogenides (TMDCs) are crucial for advanced electronic and optoelectronic devices.
• Monolayer TMDCs have limitations due to low dielectric properties, hindering carrier generation.
• Multilayer TMDCs offer potential for high-performance devices due to degenerate semiconductor properties.

Purpose of the Study:

• To fabricate and investigate the transport properties of multilayer TMDC-based in-plane heterostructures.
• To explore the potential of multilayer TMDCs for overcoming limitations of monolayer devices.
• To understand the band alignment and carrier transport at heterointerfaces.

Main Methods:

• Chemical vapor deposition (CVD) for growing multilayer MoS2 on WSe2 or NbMo1-xS2 flakes.
• Mechanical exfoliation of multilayer TMDC flakes.
• Cross-sectional high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) for structural analysis.
• Electrical transport measurements to probe interface properties.
• First-principles calculations to support experimental findings.

Main Results:

• Fabrication of multilayer in-plane heterostructures of WSe2/MoS2 and NbMo1-xS2/MoS2.
• Confirmation of abrupt composition change at the WSe2/MoS2 interface via HAADF-STEM.
• Observation of tunneling current at the NbMo1-xS2/MoS2 in-plane heterointerface.
• Demonstration of tunable band alignment (staggered to broken gap) via electrostatic doping.
• Experimental and theoretical validation of staggered gap band alignment in NbMo1-xS2/MoS2.

Conclusions:

• Multilayer TMDC in-plane heterostructures are successfully fabricated, offering advantages over monolayers.
• Tunable band alignment at heterointerfaces is achievable through electrostatic doping.
• These findings pave the way for novel electronic device applications utilizing multilayer TMDCs.