Resistive Switching in Polyvinylpyrrolidone/Molybdenum Disulfide Composite-Based Memory Devices
Zolile Wiseman Dlamini, S. Vallabhapurapu, A. Srinivasan, Shuying Wu, Vijaya Srinivasu Vallabhapurapu
Abstract
Four types of resistive random access memory structures with an active layer comprising: (1) MoS2 (device A), ( A study of resistive switching and electrical conduction mechanisms of these resistive random access memory modules revealed that devices A and B did not exhibit switching characteristics. Device C showed a combination of bipolar and threshold switching with a low switching voltage of 0.40 V. Device G portrayed bipolar switching at 0.56 V. In device C, space charge-limited conduction with a transition voltage Vtr = 0.24 V was observed, whereas in device G, Ohmic behaviour between 0.0 and 0.22 V, followed by trapping of charge in the 0.22-0.56 V regime before switching, was noticed. Both devices C and G showed a reasonable ( 10 2 ) ON/OFF ratio. In nanocomposite devices, an increase in MoS2 content resulted in an increase in electrical conductivity in the Ohmic region, leading to threshold switching at 30 wt% (device F) and ultimately bipolar switching at 40 wt% (device G). These studies have shown that both switching and conduction mechanisms are sensitive to the type and composition of the active layer in the devices studied.