Resistive switching mechanism of MoS2 based atomristor.

The non-volatile resistive switching process of a MoS2 based atomristor with a vertical structure is investigated by first-principles calculations. It is found that the monolayer MoS2 with S vacancy defects (Vs) could maintain an insulation characteristic and a high resistance state (HRS) is also remained. As an electrode metal atom adsorbed on MoS2 monolayer, the semi-conductive filament is formed with the assistance of Vs. 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 than that of without filament (HRS). The energy barrier for an Au-atom to penetrate the monolayer MoS2 via Vs is as high as 6.991 eV. When it comes to double S vacancy (Vs2), the energy barrier is still amounted to 3.554 eV, which manifests the bridge-like full conductive filaments cannot form in monolayer MoS2 based atomristor. The investigation here promotes the atomistic understanding of the resistive switching properties about the monolayer MoS2 based memristor. The physics behind should also work in atomristors based on other monolayer transitional metal dichalcogenides, like WeSe2 and MoTe2. The investigation here will promote the comprehension of these devices at atomic scale and be a reference for device design or optimization.