Moiré Engineering of Interlayer Coupling in WS₂/MoS₂ Monolayers.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Moiré superlattices offer tunable electronic band structures and material properties via interlayer couplings.
• These superlattices show promise for optoelectronic applications like color tuning and light harvesting.
• Experimental control over moiré potentials in heterostructures remains a significant challenge.

Purpose of the Study:

• To systematically investigate the dynamic modification of interlayer couplings in WS2/MoS2 heterobilayers.
• To explore the influence of excitation power and gate voltage on moiré potentials.
• To demonstrate experimental control over moiré potentials for optoelectronic device applications.

Main Methods:

• Systematic modification of interlayer couplings in WS2/MoS2 heterobilayers.
• Adjustment of excitation power and gate voltage to control moiré potentials.
• Photoluminescence (PL) measurements at varying gate voltages and excitation powers.
• Theoretical simulations to verify experimental observations.

Main Results:

• Increasing excitation power reduces effective moiré potentials by altering moiré trap filling.
• Reduced moiré potentials suppress interlayer charge transfer and p-doping effects.
• Power-dependent PL measurements showed a decreased sublinear slope with increasing gate voltage (0.63 to 0.52), indicating enhanced moiré localization.
• Theoretical simulations confirmed the gate-tuned control over moiré potentials.

Conclusions:

• Excitation power and gate voltage are effective means to dynamically tune moiré potentials in WS2/MoS2 heterobilayers.
• This control over interlayer couplings is essential for designing next-generation optoelectronic devices.
• The findings provide a pathway for experimental realization of tunable moiré superlattices.