Research On The Preparation And Performance Of Memristor Based On Two-dimensional Material

With the gradual failure of Moore’s law,traditional silicon-based devices have gradually been unable to meet the requirements of mass information storage and data processing in the future.Memristors have received considerable attention in information storage and neuromorphic computing.The emerging two-dimensional van der Waals layered materials are promising candidates in nano-electronic devices due to their excellent properties,such as high carrier mobility,reliability,and ultrathin thickness to a single layer.Benefiting from the advantages of stable structure,relatively tunable bandgap,and high mobility of carriers in Transition metal dichalcogenides,band modulation（TMDs）,enormous effort has been devoted to exploring non-volatile resistance-switching random-access memory by using TMDs as an active layer.This paper focuses on exploring the performance of memristors based on two-dimensional materials,and the specific research work is as follows:（1）Research based on MoSe₂-based memristors.From the electrical transport measurements of the device,it is concluded that the performance of the Ag/MoSe₂/Au memristor is less outstanding,with only no more than 10 times the resistive switching,and the performance is subject to large losses from the applied voltage.The cyclic test performance and stability are severely weakened,the device cannot withstand long-term voltage,and the retention of the device is not prominent enough.The working mechanism of the MoSe₂ memristor is analyzed.The conclusion is that the lattice damage of the conducting filaments to the material needs to be eliminated,thereby enhancing the performance of the device.（2）Research based on MoSe₂/graphene heterojunction-based memristors.Since graphene possesses unique properties such as good electrical conductivity,high thermal conductivity,and stable nature,its performance is improved by introducing graphene as the electrode of the memristors.A series of electrical transport measurements were performed on the device,and the measurements were good.The I-V cycle test of the device exceeds 55 cycles,and the resistive switching ratio exceeds 10²and even can reach 10⁶.but the performance of the device has a large instability.The MoSe₂/graphene heterojunction memristor with the introduction of graphene as the electrode has significantly improved performance from the electrical transport measurements,and the source of the memristor characteristics of the MoSe₂/graphene heterojunction memristor is still the conducting filament.Although the introduction of graphene enhances the performance of the device,the stability and retention of the device are still difficult to maintain due to the damage of the conducting filament to the material itself.Eliminating the lattice loss of the conductive filament to the material is one of the keys to enhancing the device’s performance.（3）Research of a novel memristor based on two-dimensional MoSe₂/MoS₂ heterojunction.By introducing the heterojunction,the damage to the material from the conducting filament is eliminated,and the key performance indicators such as retention and stability of the device are improved.This work focuses on the basic memristor performance of MoSe₂/MoS₂ heterojunction metal/heterojunction/metal（MHM）structured memristors with a high switching ratio（>10³）,good sustainability（more than 60 cycles）,and stable retention performance（2000 s）.the MHM structured memristors have comparable performance to conventional TMDs memristors.The non-volatile resistance switch of MHM structured memristors is attributed to the modulation of the energy band structure of MoSe₂/MoS₂ heterojunction.The mild energy band modulation of MoSe₂/MoS₂heterojunction improves and avoids the material damage caused by the formation and breakage of conducting filaments inside the functional layer material in conventional two-dimensional memristors.This results in a longer lifetime and more stable performance of MoSe₂/MoS₂ heterojunctions as memristors than conventional TMDs memristors.In addition to basic voltage-current measurements,pulses were applied to the device,and the fundamental synaptic behavior of the memristor was found to have prominent voltage pulse potentiation and suppression by pulsed voltage simulation.