Volatile MoS${_2}$ Memristors with Lateral Silver Ion Migration for Artificial Neuron Applications

TL;DR

This paper introduces a new type of volatile memristor based on multilayer MoS₂ grown by MOCVD, capable of forming-free operation, fast switching, and potential use as artificial neurons in neuromorphic computing.

Contribution

It demonstrates repeatable, forming-free volatile resistive switching in multilayer MoS₂ devices with detailed mechanistic insights and a physics-based model for neuromorphic applications.

Findings

Reproducible volatile RS with low voltage (~2 V)

Fast switching times down to 130 ns

Potential application as artificial neurons

Abstract

Layered two-dimensional (2D) semiconductors have shown enhanced ion migration capabilities along their van der Waals (vdW) gaps and on their surfaces. This effect can be employed for resistive switching (RS) in devices for emerging memories, selectors, and neuromorphic computing. To date, all lateral molybdenum disulfide (MoS${_2}$)-based volatile RS devices with silver (Ag) ion migration have been demonstrated using exfoliated, single-crystal MoS${_2}$ flakes requiring a forming step to enable RS. Here, we present volatile RS with multilayer MoS${_2}$ grown by metal-organic chemical vapor deposition (MOCVD) with repeatable forming-free operation. The devices show highly reproducible volatile RS with low operating voltages of approximately 2 V and fast switching times down to 130 ns considering their micrometer scale dimensions. We investigate the switching mechanism based on Ag ion surface migration through transmission electron microscopy, electronic transport modeling, and density functional theory. Finally, we develop a physics-based compact model and explore the implementation of our volatile memristors as artificial neurons in neuromorphic systems.