Research On Resistive Switching Effect Based On Two-Dimensional CuCrP₂S₆

As the fourth basic circuit component besides capacitors,resistors,and inductors,memristors have the characteristics of high storage density,fast switching speed,and low power consumption,and have become a research hotspot in today’s academic community.There are many types of memristors,among which ferroelectric memristors and filament-type memristors have been widely studied.Electrical memristors have the advantages of high concentration and low efficiency,and fine memristors also show great potential in terms of read speed and storage density.Due to the existence of dangling bonds and leakage currents caused by quantum penetration,memory devices based on three-dimensional materials are facing great challenges in the process of miniaturization.The ultra-thin raw material structure of two-dimensional materials solves these problems well.CuCrP₂S₆ is a new type of two-dimensional layered iron semiconductor material,which can maintain its original properties（such as ferroelectricity）when it is stripped into the smallest layer Therefore,this paper mainly focuses on the research of CuCrP₂S₆ in ferroelectric memristor and filament memristor,the content is as follows:（1）Preparation and characterization of CuCrP₂S₆ material.High-quality single-crystal CuCrP₂S₆ was successfully prepared using chemical vapor transport method.And X-ray diffraction and energy-dispersive spectroscopy were used to determine the phase,crystalline quality,and composition of the single crystal.The thin-layer CuCrP₂S₆ was obtained by mechanical exfoliation.Thickness-dependent Raman spectra of CuCrP₂S₆are investigated.Piezoresponse force microscopy confirms the room-temperature out-of-plane ferroelectricity of the few-layer CuCrP₂S₆.（2）Exploration of ferroelectric diodes based on device Au/CuCrP₂S₆/Au.We have prepared a CuCrP₂S₆vertical structure ferroelectric device,which exhibits the rectification characteristics of a diode,and the rectification direction can be changed by changing the polarization direction.The rectification direction of the device and the appearance of the memristor effect are attributed to the regulation of the interface Schottky barrier by the reversal of ferroelectric polarization.We also explored the application of this device in the field of artificial synapses.（3）Exploration of resistance switching characteristics based on the device Ag/CuCrP₂S₆/Au.We have realized the use of ferroelectric flip to regulate the Schottky barrier at the interface,and preliminarily realized the Memristor function（switch ratio is 10）.In order to improve the switching performance of Memristor,we improved the device:the top electrode was replaced with active metal Ag according to the chemical ion migration model.This device exhibits excellent non volatile resistance variation performance,with a switching ratio of up to 10⁶,which is 5 orders of magnitude higher than the previous device.In addition,this device also has excellent retention characteristics（10⁵ s）.We prepared a set of comparative experiments that excluded the possibility of the material itself affecting the resistance to change performance.This provides a broader vision for realizing high storage density nonvolatile Memristor.