Research On Controllable Growth Of Two-dimensional MoS₂ And Its Memristive Characteristics

In the information age,the amount of information that humans process in a single day is as large as the total recorded amount in ancient times for two thousand years,which even increasing by 28% a year.Due to the huge amount of data,the‘storage wall'problem of traditional von Neumann computing architecture is increasingly prominent.Modern information processing urgently needs a new architecture with fast processing speed to solve this problem.Artificial neural network has been the hotpot of breaking through von Neumann architecture for its special characteristics.While the two-dimensional MoS₂ memristor demonstrates its potential in simulating synapses and building neural networks.In order to achieve the practical application of MoS₂ memristor,the controllable growth of high-quality MoS₂ with large area should be achieved.To study the growth mechanism to guide the controllable preparation of MoS₂growth as a safeguard.The study and improvement of the performance of MoS₂memristor devices is aimed at laying a foundation for practical application.The article will explore the following two points:1.Exploring the growth and mechanism of CVD preparing controllable growth of high-quality MoS₂with large area.The chemical vapor deposition(CVD)method was used to explore the growth of large area single-layer MoS₂ on SiO₂/Si substrates,and the law of the CVD growth process was explored,taking the gas flow and distance between precursor and substrate as variables.By adjusting the gas flow and distance,MoS₂ samples with different layers,grain size and nucleation density were obtained,respectively.Through a variety of characterization methods(XPS,AFM,TEM,etc.),it is proved that the CVD MoS₂ samples were analyzed to explore growing mechanism of CVD method.The growth mechanism of MoS₂ grown by CVD method was deeply explored through the characterization of experimental samples.The gas flow affects the layer number and grain size of MoS₂ layers while the change of the distance between precursor and substrate affects the nucleation density of MoS₂.The exploration of growth mechanism during experiment has a certain significance for the realization of controllable growing high-quality and large area MoS₂ on SiO₂/Si substrates.2.Establishment and performance study on MoS₂ memristor devices.Based on the single-crystalline monolayer large-area molybdenum disulfide obtained in the experiment,lateral two-terminal memristors were designed and prepared,and the memristor property and mechanism of MoS₂ were studied systematically.After optimizing pulse testing progress,MoS₂ memristor with channel length of 2?m exhibits a wide modulation range and typical biological synaptic behavior,including excitatory/inhibitory postsynaptic currents(EPSC/IPSC),pulse-frequency dependent plasticity(SRDP),and long-term plasticity(LTP).In addition,dynamic filtering character,multi-level long-term plasticity(LTP)and low power consumption of 1.8pJ are achieved,which is the lowest power consumption compared with MoS₂ devices reported.The exploration of memristive mechanism indicates that migration of sulfur vacancies dominates the performance of MoS₂ memristor.This work shows that MoS₂ memristor can meet the needs of complex artificial synapse and neural network applications more flexibly and has certain practical value.