Bifunctional NbS₂-Based Asymmetric Heterostructure for Lateral and Vertical Electronic Devices

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Layered metallic transition metal dichalcogenides (MTMDCs) are promising for electronics but limited by surface oxidation.
• Creating asymmetric structures by combining surface protection and oxidation in MTMDCs is underexplored.

Purpose of the Study:

• To report a bifunctional NbS2-based vertical heterostructure with simultaneous high-efficiency tunneling conductive and memristive surfaces.
• To explore the potential of such structures in advanced electronic devices.

Main Methods:

• Epitaxial growth of NbS2 on MoS2.
• Natural oxidation to form a MoS2-NbS2-NbOx heterostructure.
• Fabrication and characterization of lateral transistors and memristors.

Main Results:

• The heterostructure exhibits a tunneling conductive surface, enhancing lateral transistor mobility by ~140 times compared to exfoliated NbS2 contacts.
• The memristive surface enables high-performance lateral and vertical memristors with low operating voltages and synaptic functions.
• A memristor array for nonvolatile memory was developed, demonstrating good endurance (2000 bending cycles) for flexible devices.

Conclusions:

• The bifunctional heterostructure offers a novel strategy for creating asymmetric materials.
• This approach paves the way for future applications of layered metallic materials in electronics and memory devices.