Research On Interface Modulation And Properties Of Halide Perovskite CH₃NH₃PbI₃ Resistive Random Access Memory

With the advent of the 5G era,big data applications are developing rapidly,but it also brings higher requirements for data storage.At present,the flash memory widely used in daily life has faced the limit of its size reduction,researchers are investing a lot of research into the next generation of memory technology.Resistive random access memory（RRAM）is considered to be the leader in the next generation memory competition because of its high storage density,fast operation speed,low power consumption and easy integration.In recent years,halide perovskites have been widely used in optoelectronic devices due to their advantages of simple preparation,high charge mobility and large absorption coefficient.In order to explore the application of halide perovskite materials in the resistive memory more comprehensively,this thesis selected RRAM device based on methylammonium lead iodide（CH₃NH₃PbI₃）material to study its resistive switching（RS）behavior and interface modulation.The main results of the experiment are as follows:（1）High quality CH₃NH₃PbI₃ thin films were prepared on ITO surface by one-step spin coating method,then Ag/CH₃NH₃PbI₃/ITO structure RRAM was constructed.After electrical initialization,the device exhibited typical bipolar RS behavior.At the same time,the device possessed low Set voltage（about-0.4 V）and Reset voltage（about 0.25 V）,an endurance of 50 cycles,an on-off ratio of 10,a data retention time of 700 s.（2）Based on the prepared Ag/CH₃NH₃PbI₃/ITO memory,LiF layer,ZnO layer,2D PEA₂PbI₄ layer and PMMA layer were inserted into the interface of CH₃NH₃PbI₃and Ag respectively to optimize the RS performance of the device.The results show that the Ag/ZnO/CH₃NH₃PbI₃/ITO structure RRAM has the best RS performance.The device exhibited excellent performance with an endurance of 100 cycles,a high on-off ratio of 10²,a data retention time of 1500 s,and a longterm air stability for 21 days,showing good application potential.The device conforms to ohmic conduction characteristics in the low-resistance state,and satisfies the space charge-limited current conduction（SCLC）mechanism in the high-resistance state due to the trapping of charges by interface defects.（3）Similarly,based on the above method,ZnO layer,PMMA layer and PVDF layer were inserted into the interface of CH₃NH₃PbI₃ and ITO respectively to optimize the RS performance of the device.The results show that the RS performance of the device is significantly improved after inserting a PMMA layer with a thickness of 220nm at the interface.The Ag/CH₃NH₃PbI₃/PMMA/ITO structure RRAM has a low operating voltage（-0.3 V～0.4 V）,an on-off ratio of 10³,and a data retention time greater than 1500 s,showing good repeatability and stability.