Volatile MoS₂ Memristors with Lateral Silver Ion Migration for Artificial Neuron Applications

Area of Science:

• Materials Science and Engineering
• Nanotechnology
• Solid-State Electronics

Background:

• Layered two-dimensional (2D) semiconductors facilitate ion migration along van der Waals (vdW) gaps and surfaces.
• This ion migration property is crucial for resistive switching (RS) in emerging memory, selector, and neuromorphic computing devices.
• Previous lateral molybdenum disulfide (MoS2)-based volatile RS devices relied on exfoliated single crystals and required a forming step.

Purpose of the Study:

• To demonstrate repeatable, forming-free volatile resistive switching (RS) in multilayer MoS2 devices.
• To investigate the underlying Ag ion migration mechanism in MOCVD-grown MoS2.
• To develop a physics-based compact model and explore neuromorphic applications.

Main Methods:

• Fabrication of multilayer MoS2 devices using metal-organic chemical vapor deposition (MOCVD).
• Characterization of volatile RS behavior, including operating voltage and switching speed.
• Investigation of the switching mechanism using transmission electron microscopy (TEM), electronic transport modeling, and density functional theory (DFT).

Main Results:

• Achieved highly reproducible, forming-free volatile RS in MOCVD-grown multilayer MoS2.
• Demonstrated low operating voltages (≈2 V) and fast switching times (down to 130 ns) for micrometer-scale devices.
• Identified Ag ion surface migration as the primary switching mechanism.

Conclusions:

• MOCVD-grown multilayer MoS2 offers a promising platform for forming-free, volatile resistive switching devices.
• The developed devices show potential for high-performance neuromorphic computing applications.
• A physics-based compact model facilitates the understanding and design of such memristive systems.