Resistive switching mechanism of MoS2based atomristor.

ABSTRACT

The non-volatile resistive switching process of a MoS2based atomristor with a vertical structure is investigated by first-principles calculations. It is found that the monolayer MoS2with a S vacancy defect (VS) could maintain an insulation characteristic and a high resistance state (HRS) is remained. As an electrode metal atom is adsorbed on the MoS2monolayer, the semi-conductive filament is formed with the assistance ofVS. Under this condition, the atomristor presents a low resistance state (LRS). The ON state current of this semi-filament is increased close to two orders of magnitude larger than that without the filament. The energy barrier for an Au-atom to penetrate the monolayer MoS2viaVSis as high as 6.991 eV. When it comes to a double S vacancy (VS2), the energy barrier is still amounted to 3.554 eV, which manifests the bridge-like full conductive filament cannot form in monolayer MoS2based atomristor. The investigation here promotes the atomic level understanding of the resistive switching properties about the monolayer MoS2based memristor. The physics behind should also work in atomristors based on other monolayer transition-metal dichalcogenides, like WSe2and MoTe2. The investigation will be a reference for atomristor-device design or optimization.