Mechanisms of Resistive Switching in 2D Monolayer and Multilayer Materials

TL;DR

This review explores the diverse resistive switching mechanisms in 2D layered materials, emphasizing atomic-level processes, defect roles, and interface effects, to guide future low-energy memory device development.

Contribution

It classifies and analyzes various resistive switching mechanisms in 2D materials, focusing on atomic and defect-related processes, and discusses challenges and prospects for device applications.

Findings

Multiple switching mechanisms coexist in 2D layered materials.

Atomristor-type switching involves atomic motions at interfaces.

Understanding defect and interface roles is key for device optimization.

Abstract

The power and energy consumption of resistive switching devices can be lowered by reducing their active layer dimensions. Efforts to push this low-energy switching property to its limits have led to the investigation of active regions made with two-dimensional layered materials (2DLM). Despite their small dimensions, 2DLM exhibit a rich variety of switching mechanisms, each involving different types of atomic structure reconfigurations. In this review, we highlight and classify the mechanisms of resistive switching in mono and bulk 2DLM, with a subsequent focus on those occurring in a monolayer and/or localized to point defects in the crystalline sheet. We discuss the complex energetics involved in these fundamentally defect-assisted processes, including the co-existence of multiple mechanisms and influence of the contacts used. Examining the highly localized 'atomristor'-type switching, we provide insights into the atomic motions and electronic transport across the metal-2D interfaces underlying their operation. Finally, we present the progress and our perspective on the challenges associated with the development of 2D resistive switching devices. Promising application areas and material systems are identified and suggested for further research.