Charge Transport in MoS₂/WSe₂ van der Waals Heterostructure with Tunable Inversion Layer

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Understanding charge transport and photoinduced currents in 2D van der Waals heterostructures is crucial but remains incomplete, especially concerning interface charge layers.
• Molybdenum disulfide/tungsten diselenide (MoS₂/WSe₂) heterostructures are promising for electronic and optoelectronic applications.

Purpose of the Study:

• To investigate the transport properties of a multilayer MoS₂/WSe₂ heterojunction.
• To elucidate the mechanisms of charge transport influenced by tunable charge inversion/depletion layers at the interface.

Main Methods:

• Fabrication of a multilayer MoS₂/WSe₂ heterojunction.
• Tuning of charge inversion/depletion layers using back-gate bias.
• Characterization via Raman spectroscopy and electrical transport measurements.
• Photocurrent measurements to analyze device behavior.

Main Results:

• A tunable charge inversion layer was successfully constructed at the WSe₂ surface, with depletion regions characterized in both MoS₂ and WSe₂ layers.
• Charge transport was found to involve both tunneling and recombination regimes, influenced by the inversion layer.
• Photocurrent measurements indicated recombination and space-charge-limited behaviors, analogous to organic semiconductor heterostructures.

Conclusions:

• The study provides a deeper understanding of charge transport mechanisms in MoS₂/WSe₂ heterostructures, particularly the role of tunable interface charge layers.
• Findings contribute to the broader research on van der Waals heterostructures and their potential applications in advanced electronic and optoelectronic devices.