Study On Resistive Storage And Neurosynaptic Biomimetic Devices Based On Graphene Oxide Quantum Dots

Memristor is the fourth basic electronic component proposed by Cai Shaotang.Its resistance can be changed according to the amount of charge flowing through it.Because of the unique characteristics of memristors,the research on them extends to many aspects.Resistance random access memory?RRAM?is an important application of memristors in memory field.Because of its simple structure,fast speed,low power consumption,and compatibility of fabrication process with the existing VLSI chip production process,RRAM has become a prominent advantage as one of the possible choices of next-generation memory.However,there are many obstacles in the process of industrialization of resistance memory.Among them,the most prominent problem is that the switching threshold voltage?Set and Reset?of resistance memory has greater dispersion.Therefore,the research and preparation of new resistance devices with better performance and higher uniformity of switching threshold voltage is the focus in the field of RRAM.Another application of memristors is the study of synaptic bionics,which imitates the synaptic behavior of human brain,such as memory,forgetting and synaptic plasticity.The study of synaptic bionic devices is of great significance for brain-like computing.In order to meet the research needs in the field of rheological storage and synaptic bionic devices,the following three research works have been done in this paper.Firstly,using graphene oxide quantum dots?GOQDs?,combined with the traditional resistance functional layer material Zr_0.5Hf_0.5O₂?ZHO?,GOQDs were embedded in ZHO thin films,and a new type of resistance devices with Ag/ZHO/GOQDs/ZHO/Pt stacking structure was prepared for the first time.Compared with the traditional Ag/ZHO/Pt device,the new device exhibits reversible bipolar resistive switch?RS?behavior under direcr current?DC?scanning voltage.The Set/Reset voltage of the device is significantly lower,and the numerical distribution of Set/Reset voltage is more centralized,and the uniformity is greatly enhanced.In addition,the data retention ability and switching speed of the device are further improved.At the same time,the physical mechanism of the device performance improvement is also studied in this paper.The performance improvement is due to the local enhanced electric field by the embedded GOQDs.Secondly,based on the research that GOQDs can lead to a great improvement in the performance of RRAM devices,a novel memristor with Ag/Zr_0.5Hf_0.5O₂:GOQDs/Ag structure was fabricated by innovatively changing the device structure,which enables the device to successfully conduct bi-directional progressive control of conductance under the action of pulses with amplitude of 0.6V and width of 30ns.It is found that the device can be regulated approximately linearly under the action of low-energy pulses.The prominent advantages of linear conductivity regulation are presented.On the basis of the bi-directional progressive regulation of the memristor conductance,the synaptic functions such as spiking-timing-dependent plasticity?STDP?and paired-pulse facilitation?PPF?are simulated using the new memristor.By studying the microcosmic mechanism of device conductance change,it is revealed that the interaction of tunneling mechanism and electrochemical metallization effect is an important factor leading to the continuous and progressive regulation of the conductance of the memristor.This work provides a new method for fabricating memristors with fast conductivity regulation under low energy consumption.Thirdly,in view of the advantages of wide bandgap and good stability of SiC materials,this paper introduces SiC into the field of RRAM research for the first time,and fabricates a new type of Al/ZrO₂/SiC resistor device based on SiC.It is found that the device has a large working voltage and is suitable for high-power application scenarios.It also has good multi-resistance storage capability.Moreover,because of its unique rectification effect,the device can effectively reduce the adverse effects of parasitic current on the device.The stability of high resistivity storage is conducive to large-scale integration.At the same time,it is found that the switching voltage after the GOQDs was embedded in the device is further reduced.