Polyethyleneimine (PEI) Based Atomic Switch Memristor

With the emergence of artificial intelligence(AI)and the Internet of Things(IOT),it is difficult for current mature storage technologies to cope with the upcoming explosion of massive amounts of data.This current situation has created a strong demand for new types of memory.It is expected that the memory can combine the advantages of dynamic random access memory(DRAM),hard disk drive(HDD)and flash memory,with high erasing and writing speed,high density integration and non-compliance.At the same time,with the rapid development of wearable devices,the current silicon-based semiconductor memory still has major shortcomings in data retention,high-density integration,flexibility,etc.,and cannot meet the requirements for wearable or even wearable devices.The actual demand for the use of implanted personal healthcare smart devices.Therefore,for academia and industry,researching new materials and new devices to meet future memory needs has become a top priority.In this paper,this new type of device principle memory-ion-based memristor based on ion migration is studied.The application of organic polymer solid electrolytes in memristors has broad prospects.However,polymer solid electrolytes are easily decomposed under heat treatment and their ionic conductivity changes greatly at different temperatures.Therefore,in the reported research on organic polymer memristors,most of the results show that such devices generally lack repeatability,durability and stability,and cannot work within a large temperature range.Although organic polymer memristors have made some progress in terms of thermal stability,there is still a huge gap compared with inorganic memristors.However,the resistance change layer of an organic polymer memristor can adjust its electrical properties through molecular design and synthesis methods,and the preparation process of the organic memristor is simple,and its inherent flexibility and biocompatibility make the organic polymer memristor suitable The best choice for wearable and implantable devices.Therefore,the research of polymer-based memristors is very necessary.In view of the above problems,a suitable organic polymer electrolyte is selected to improve its function to improve the performance of the organic polymer atomic switch memristor.The research content includes:(1)From the molecular point of view of polymer design and selection,polymer polyethyleneimine(PEI)is selected as the medium layer.PEI exists in the form of a rigid structure,formed by hydrogen bonds between adjacent charged amine groups to form a relatively stable six-membered ring with strong thermal stability.In addition,due to its polar(amino)and hydrophobic(vinyl)group structure,it can be combined with different substances.Therefore,PEI exhibits high ionic conductivity at both room temperature and high temperature.As a result,Ag/PEI/Pt devices were fabricated to study their electrical properties at room temperature and high temperature.At the same time,the morphology of the conductive filaments formed by the planar devices after the first SET was observed and analyzed by field emission scanning electron microscope(FESEM).In this study,the atomic switch memristor using Ag / PEI / Pt structure exhibited excellent performance(high ON/OFF ratio,low power consumption,non-volatility and Good retention).In addition,in-situ Raman spectroscopy,in-situ X-ray diffraction(XRD)and differential scanning calorimetry(DSC)have been used to study the root causes of the instability and failure of PEI atomic switch memristors at higher temperatures.(2)Based on the inherent flexibility of the PEI film,a flexible PI substrate with good mechanical properties and high temperature resistance was selected to study the I-V characteristics of the device at different temperatures and the I-V characteristics under different bending times.It is found that the Ag/PEI/Pt/PI flexible atomic switch memristor is tested at 150°C after being bent 2000 times,and the device still maintains the original switching performance.In addition,the scanning electron microscope image of the electrode intersection at the bend and the scanning electron microscope image after 2000 bending were compared by SEM.It was found that no cracks occurred at the electrode intersection,and the reason for the absence of cracks was analyzed.(3)Based on the excellent performance of semiconductor quantum dots,Ag /PEI + BNQDs / Pt and Ag / PVP + BNQDs / Pt atomic switch memristors were fabricated by doping boron nitride quantum dots(BNQDs),and tested under room temperature air environment The IV characteristics and doping concentration of PEI have an effect on the performance of the device.It is found that the device made of PEI+100u LBNQDs can circulate 6,000 times stably in an air environment at room temperature,and after being placed in an air environment and room temperature for one month,the device can still cycle 1,000 times.