First-Principles Investigation of the Resistive Switching Energetics in Monolayer MoS₂: Insights into Metal Diffusion and Adsorption

A deeper understanding of resistive switching (RS) in 2D materials is essential for advancing neuromorphic computing. The Dissociation-Diffusion-Adsorption (DDA) model offers a useful framework for probing RS mechanisms in non-volatile memory (NVM) and in-memory computing. We have employed first-principles density functional theory (DFT) to explore dissociation, diffusion, and adsorption phenomena within the DDA model, focusing on the interactions between exemplary metal atoms (Au, Ag, Cu) and monolayer MoS₂. Nudged elastic band (NEB) calculations evaluated diffusion barriers in pristine and sulfur-vacancy MoS₂. Charged systems were modeled to assess the impact of applied bias on migration pathways. We also examined metal dissociation from bulk electrodes and adsorption at S vacancies. Ag/MoS₂ shows the lowest dissociation barrier (~0.034 eV), while Au and Cu exhibit similar values (~0.32 eV). For diffusion, Ag also exhibits the lowest barrier (~0.07 eV) across both pristine and S-vacancy MoS₂, further supporting its low-energy RS behavior. Silver’s switching energy is only ~2× the Landauer limit, underscoring its potential for ultra-low-power resistive switching and guiding the optimization of 2D memory devices.