Research On The First Pinciple Of Memristor Material Characteristics

Adding to the social changes today is the appearance of a stockpile of information,the traditional storages are facing the unprecedented challenge of high speed,large capacity and diverse demands.The appearance of memristor have given people new idea and hope.Compare with traditional storages,memristor have more advantages to become the next generation information storages,due to its higher speed,larger capacity,lower power design and so on.Besides, memristor can realize the integration of storage and computing,the preparation of neurons synaptic function device,a logic operation,etc.Above all,Research institutions and semiconductor manufacturers consider memristor as the next generation new electronic intelligence storage devices.At present,people have done a series of researchs on memristor’s materials, devices and applications.However, the uncertainty of nano-scale electric-transport mechanism leads to the divergence of memristor’s mechanism. This situation restrict memristor’s research and application.And there have few researchs on memristor’s nonlinear resistance change characteristics,using theoretical calculation,based on memristor’s characteristics and building device models.,This paper,based on density functional theory and the band structure theory, use First principles theory and Non-equilibrium Green Function(NEGF) set up a memristor’material analog scheme,using Atomistix ToolKit (ATK) to simulate memristor’s eletronic characteristic,analysing memristor material nano-scale electric-transport mechanism and discussing memristor nonlinear resistance change mechanism.Based on a memristor simulate plan,we simulate CuOx memristor and chalcogenide memristor,set up Ag electrode-CuOx and Ag electrode-Ge2Sb2Tes double electrodes system structure.Further,we use ATK to simulate Ag-CuOx-Ag and Ag-Ge2Sb2Te5-Ag doulble electrodes system’s electronic characteristic,use the simulation data to analysis memristor nonlinear resistance change mechanism. On the other hand, we set up a comparative simulation with Ag-CuO-Ag and Ag-CuOx-Ag’s Ⅰ-Ⅴ characteristics Through the simulation data,we can find out that the mechanism of CuOx memristor nano-scale electric-transport is the change of contact interface by Ohmic contact to Schottky contact because of the electrode and the functional material’s contact in voltage under the effect of boundary transfer effect.Thirdly,we simulate Ge2Sb2Tes memristor material compare with a crystal model and a amorphous model’s Ⅰ-Ⅴ characteristics.Based on the simulation data, we find out due to the large amount of empty seats in GST model,the defect effect cause the nonlinear memristor mechanism of Ge2Sb2Tes.Besides,Ag electrode dop in the Ge2Sb2Tes space make the material to present memristor characteristics.The above memristor simulation scheme and conclusions provide us a new idea and important theoretical reference on memristor mechanism.