Study Of Mxene/SiO₂-Based Memristor And The Synaptic Bionic Application

Under the background of the developing information society,the power consumption and computational efficiency of dominant von Neumann hardware systems restrict the development of artificial intelligence centered on massive data.It is expected that the neuromorphic computing,which follows the working mode of human brain,will break through these bottlenecks and build the Computing-in-Memory system with high efficiency and low power consumption.Memristor,as a key component in the construction of neuromorphic system,is considered as one of the most competitive candidates in neuromorphic devices.However,the oxide-based memristors dominated by conductive filaments have their inherent limitations,which restrict the further development of these devices.In this work,a novel 2D material MXene is introduced into SiO₂-based devices to optimize discrete resistance states and relatively high SET voltages.The main work is as follows:(1)MXene(Ti₃C₂T_x)was investigated to explore its compatibility with SiO₂ in terms of materials and processes.Ti₃C₂T_x powder was prepared by etching Ti₃Al C₂ and a series of physical characterization such as SEM,XRD,FT-IR was conducted.The MXene layer with a thinkness of 50nm can be introduced into the fabrication of memristors by spin-coating.(2)The Cu/MXene/SiO_2/W and Cu/SiO₂/W devices with single structure were fabricated by magnetron sputtering and spin-coating,and a series of electrical measurements were performed to compare the difference between their characteristics to explore the impact of the introduction of MXene.Devices based on MXene/SiO₂ structure exhibit better stability,uniformity and data retention with stable multi-resistance states.The conduction mechanism of the device is analyzed by combining first-principles calculation with the growth kinetics of Cu filaments.Finally,conductance modulation with good linearity is realized under DC and pulse stimulations.(3)In order to decrease the power consumption,the Ti N/Ag/MXene/SiO₂/Pt crossbar devices were fabricated,which are volatile under I_CC=1 n A and have ultra low power consumption of 0.06n W.The volatile behavior can correspond to the short-term plasticity of biological synapses.The devices exhibit good nonvolatile characteristics under I_CC>100?A.On this condition,the window of R_OFF/R_ON is about 10³ and the retention time is longer than 10⁴ s.Besides,the value of V_SET is as low as 0.2 V.The nonvolatile behavior can correspond to the long-term plasticity of biological synapses.The influence of the shapes of CFs is analyzed to explain the coexistence of the volatile behavior and nonvolatile behavior.Finally,better conductance modulation and SRDP can be achieved by adjusting the stimulation parameters.What is more,short-term plasticity(including PPF,PPD,the transition from short-term enhancement to depression),long-term plasticity(including STDP)and the training process of memory enhancement can be achieved in these devices.