Study On The Switching Mechanism Of Molybdenum Disulfide-based Flexible And Transferable Resistive Switching Memory

Conventional flash memories with floating gates will reach their physical limitations with the process of miniaturization.Developing high-density next generation non-volatile memories has attracted great attention.Resistive random access memory?RRAM?in which the evolution of conductive filament takes place at nanosized region,has great potential in high density data storage field.In addition,the RRAM also exhibits fascinating characteristics such as fast operation speed,high endurance,long-time retention and low energy consumption.The insulating layer of RRAM usually has great influences on its performance,which has draw great attention for researchers.Among the potentional materials for RRAM,molybdenum disulfide?MoS2?has enormous advantages in flexible electronics owing to its simple fabrication process,good mechanical flexibility and easy to control the electrical properties.However,the switching mechanism of MoS2-based RRAM is still not clear,which will limit its application in RRAM.In this work,we discussed the performance of MoS2-based RRAM in multilevel and flexible storage area.Furthermore,we also give a study on the switching mechanism to explain the reversible alternation between BRS and URS model.Specific study is as follows:On the study of multilevel storage performance:In this work,we constructed a Ag/MoS2/Au structure device,which exhibits a reversible alternation between BRS and URS model.Based on LRS states resulting from two different switching models,we designed a positive bias reading method to distinguish two low resistance states.In addition,multilevel resistance state can also obtained by controlling the compliance current.On the study of switching mechanism:Ag/MoS₂/Au RRAM displays two resistive switching behaviors under different voltage polarities.The double logarithmic I-V curves of LRS display a linearly Ohmic behavior for both BRS and URS,indicating the switching behavior can be attributed to the CFs model.The mechanisms of the BRS and URS modes can be attributed to the electric-field-induced migration of metal-Ag and sulfur vacancies?V_S?conducting filaments respectively,which are confirmed by investigating the temperature dependence of low resistance states and Raman spectrum in both modes.Meanwhile,we also give an activation energy measurement to explain the reversible transition between two modes.On the study of flexible properties:A transferable RRAM with water soluble substrate based on Ag/MoS2/Au construction is demonstrated for flexible applications.The flexible device exhibited a superior bending deformation tolerance,and no degradation in the electrical characteristics was observed after consecutive bending cycles.More importantly,we can transfer the device onto unconventional support through water-dissolution treatment.The result indicates that the MoS₂-based RRAM has great potential applications in future flexible and transferable electronic device field.