Low voltage resistance switching characteristics of Cu/MoS2/Cu/ITO devices

Abstract

The resistive switching behavior is observed in the Cu/MoS2/Cu/ITO structures, which has been deposited by magnetron sputtering. With the increase in MoS2 thickness, the resistive switching behavior is gradually weakened. The optimal device with a MoS2 thickness of 120[Formula: see text]nm has a lower Set voltage and Reset voltage, where Set voltage is 0.14–0.3[Formula: see text]V and Reset voltage is −0.24[Formula: see text]V to −0.08[Formula: see text]V. The device also has a resistive switching ratio of up to 105 high resistance state/low resistance state, a data retention time over 104[Formula: see text]s, and can endure more than 103 cycles. As the limiting current increases, the resistance switching (RS) characteristics of devices with MoS2 thickness of 200[Formula: see text]nm at both positive and negative biases are improved. There is no RS behavior in ITO/MoS2/ITO devices fabricated by the same method, which indicates that sulfur vacancies have little effect on the RS characteristics of Cu/MoS2/Cu/ITO devices. Moreover, since the migration barrier and diffusion activation energy of Cu in MoS2 are lower than those of sulfur vacancy, combined with the data fitting structure, it is shown that the RS behavior is formed because Cu ions control the connectivity and fracture of conductive filaments through the diffusion and migration of MoS2 layer.