Enhanced resistive switching in graphene oxide based composite thin film for nonvolatile memory applications

The uniform and stable bipolar switching characteristics of Graphene Oxide (GO) based metal insulator metal (MIM) structure embedded with titanium dioxide (TiO2) nanoparticles (NPs) on ITO/glass substrate has been investigated. In this paper the effect of TiO2 concentration on switching characteristics of Al/GO-TiO2/ITO MIM devices were studied. Thin film of composite (GO-TiO2) was deposited on conductive indium tin oxide (ITO) glass using spin coating technique. The incorporation of TiO2 NPs in GO thin film increased the number of oxygen vacancies which were responsible for formation and rupture of conducting filament between two electrodes of Aluminum and ITO. It was observed that Al/GO-TiO2 (4 mg)/ITO require low voltage to switch from OFF state (High Resistance State) to ON state (Low Resistance State) and vice versa as compared to Al/GO/ITO device. Switching behavior of the fabricated devices were investigated using current voltage characteristics. The dispersion of TiO2 (4 mg) NPs in GO reduced the switching voltage by almost 50% than the bare graphene oxide thin film. The retention behavior of fabricated device was tested upto 4*10(3) s and endurance behavior upto 60 cycles which didn't exhibit any degradation. Carrier transport mechanism in the devices has been explained on the basis of current voltage characteristics in HRS and LRS. These composite based resistive random access memory devices have great potential as a future nonvolatile low power memory.