Local Interface Effects Modulate Global Charge Order and Optical Properties of 1T-TaS₂/1H-WSe₂ Heterostructures

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• 1T-TaS2 is a charge density wave (CDW) crystal with resistance changes exploitable for data storage.
• Controlling CDW states is crucial for technological applications.
• Heterostructuring offers a route to tune CDW properties by modulating interlayer interactions.

Purpose of the Study:

• To investigate the optical and electronic properties of 1T-TaS2/1H-WSe2 heterostructures.
• To understand how varying 1T-TaS2 thickness and azimuthal alignment affects CDW states.
• To explore the impact of interlayer alignment on exciton dynamics in 1H-WSe2.

Main Methods:

• Fabrication of 1T-TaS2/1H-WSe2 heterostructures with controlled thickness and alignment.
• Systematic variation of 1T-TaS2 thickness and azimuthal angle relative to 1H-WSe2.
• Characterization of electronic and optical properties, including CDW ordering and exciton dynamics.

Main Results:

• Moiré strain and interfacial charge transfer in heterostructures introduce CDW disorder in 1T-TaS2.
• CDW ordering temperature in 1T-TaS2 is modified by heterostructuring.
• Interlayer alignment significantly impacts exciton dynamics in the 1H-WSe2 layer.

Conclusions:

• Heterostructuring 1T-TaS2 with 1H-WSe2 provides a method to tune CDW phase transitions and electronic properties.
• Interlayer alignment is a critical factor in controlling both CDW states and optical properties.
• This approach enables concurrent engineering of electronic phases in CDW materials and optical properties in semiconductors.