Study On The Resistive Switching Behavior And Performance Improvement In Graphene Oxide Based Memory

The development of the information industry has entered the era of real high-capacity data.The communication network,cloud computing,high-end electronic equipment and so on are undergoing the change,storage and processing of data every day.The most sophisticated silicon-based flash memory in memory technology has been unable to continue to meet the demands of big data growth due to its size constraints.Therefore,a variety of new types of memory have been born successively,among which the non-volatile resistance random access memory?RRAM?has become a target of close attention due to its large potential of miniaturization,high storage density,fast conversion speed and low power consumption.The RRAM basic memory cell has a structure of conductor/resistivity layer/conductor,the resistance layer is the core of the whole device,and its resistance can be changed under the voltage of the external circuit.However,due to the various kinds of resistance materials and different electrode activities,the working mechanism of RRAM devices has not been widely recognized.It is very important to explore the corresponding resistance behavior and mechanism of different resistance layers.In addition,two-dimensional materials develop rapidly,and the graphene?GO?and its derivatives are the star materials,which show the quality of the electrical properties and have great potential as a resistance switching material.Therefore,it is very important to study the GO-based memory.The mechanism of RRAM,as well as the filament theory,is based on electric field-induced-ion migration.Therefore,our work is focused on the switching kinetic process through regulating the electric field from two aspects to study the resistive switching behavior and performance improvement in GO-based memory.?i?Control the strength of the electric field and verify the essence that determines the resistive behavior of GO-based memory devices:We regulated the strength of the electric field imposed on Al/GO/ITO devices by means of two methods.First,the compliance current?CC?is the key to tune the strength of electric field applied on the switching layer,and also the degree of conversion between sp³ and sp² in GO film.The coexistence of bipolar and complementary resistive switching was demonstrated though applying the CC or not.Herein,the resistive switching in GO-based memory is originally from the transform between sp³ and sp²,which is verified from X-ray photoelectron spectroscopy?XPS?and Raman analysis.Furthermore,we varied the thickness of GO film to regulate the strength of the electric field.The CRS behavior was optimized and further illustrated to relate to limited amount of sp2induced by electric field.The relationship between different thickness devices and complementary behaviors is shown,and the mechanism of reaction is explained and proved.?ii?Control the distribution of the electric field and develop a feasible method to improve the performance of GO-based resistive switching devices:Herein,the introduction of Ag nanowires?i.e.,NWs?was proposed to improve the performance of RRAM devices.The Ag NWs play two important roles.Firstly,the large surface curvature of the Ag NWs can induce the local electric field and simplify the formation of CFs,which will increase the uniformity of parameters(i.e.,R_HRS/R_LRS/V_SET/V_RESET).Secondly,thanks to the water environment growth of Ag NWs,it follows the principle of the lowest energy and contains less internal defects.As a result,the Ag CFs constructed by pre-introduced NWs show a robust thermal retention and a good WRITE/ERASE endurance due to the tightly connective Ag atoms inside the NWs.Importantly,we designed the device with the lateral structure using lithography technique,and directly observed the local electric field effect and participation of Ag NWs during the forming process,which was confirmed by the fluorescence microscope and SEM.The doping of Ag NWs is verified to be a simple and practical method to improve the performance of GO-based resistive switching device.