Graphene band engineering for resistive random-access memory application

Emerging memory technologies promise new memories to store more data at less cost. On the other hand, the scaling of silicon-based chips approached its physical limits. Nonvolatile memory technologies, such as resistive random-access memory (RRAM), are trying to solve this problem. The fundamental study in RRAM devices still needs to be moved further. In this regard, conduction mechanism of RRAM is focused in this study. The RRAM conductance varies considerably depending on the material used in the dielectric layer and selection of electrodes. To formulate the conductance mechanism, new materials with notable conductivity such as graphene oxide (GO) sheets has been employed by researchers. In the GO-based RRAM, pristine of GO due to the presence of sp(3)-hybridized oxygen functional groups(hydroxyl) leads to electrically insulating layers in the device. However, by applying the voltage, the conductive path can be formed with the redox of GO layer in to graphene. This phenomenon is known as RRAM set process which can be explained due to the conversion of sp(3) to sp(2) oxygen functionalities, which make the RRAM to move in to the ON state. Also, in this paper, variation of the ON state resistance by the voltage in the nondegenerate mode is described and the reset process by degeneracy variation is reported.