Fig. 6: Schematic representation of two proposed switching pathways in a 2D monolayer resistive memory device.

a Scenario A illustrates the dissociation of a metal atom from the bulk, followed by diffusion across the interface into a vacancy site. b Illustrates the barrier energy vs reaction-co-ordinate graph for NEB calculation corresponding to Scenario A, i.e., dissociation of metal atom from bulk, followed by diffusion across the interface and adsorption at S vacancy site. c Scenario B shows the dissociation, followed by diffusion along the pristine 2D monolayer surface toward a vacancy site, and subsequent adsorption. d Barrier energy vs. reaction-coordinate graph illustrating diffusion of metal atoms along their respective MEPs on pristine MoS₂ surface (Teal = metal atoms, yellow = S, purple = Mo, red/orange = vacancy). In Scenario A, where the vacancy is close to the dissociating metal atom, switching occurs without an additional diffusion energy barrier, as the metal directly migrates into the monolayer. In contrast, Scenario B requires an extra diffusion step, with an additional energy cost of ~0.07 eV for Au and Ag and ~0.25 eV for Cu. The overall switching energy, governed by both dissociation and diffusion, varies by metal, with silver exhibiting the lowest barriers for both interfacial (~0.03 eV) and surface diffusion (~0.07–0.2 eV). This makes silver the most energetically favorable option for switching, regardless of the scenario.