Electric field induced tunable memristive characteristics of exfoliated graphene oxide embedded polymer nanocomposites

Abstract

Resistive switching properties of layered graphene oxides (GOs) filled polymer nanocomposites (PNCs) have received tremendous attention in the field of memory devices. Herein, we report highly stable write-once-read-many-times (WORM) resistive switching properties of exfoliated GOs embedded poly(methyl methacrylate) (PMMA) thin films. The WORM characteristics of the PNC devices have been studied by varying the active layer thickness and the content of GO nanofillers. A disrupted carbon network of GOs enables defect states that act as an energy barrier for carriers and the charge transport through the PNC devices is blocked at a lower electric field. At an elevated electric field, GO sheets embedded PMMA offers percolation pathways for electron transfer, thereby making the composites electrically more conductive. The set voltage (VSET) decreases with a decrease in the active layer thickness, whereas VSET increases with a decrease in the GOs content within PNC devices. For a fixed compliance current (∼1 μA), highest ION/IOFF ratio ∼104 at 1.87 V has been achieved for the PNCs device spin-coated at 9000 rpm with 0.1 wt. % GOs content. The stability of the devices has been confirmed through retention test up to 104 s. In addition, the J-V curves are fitted and an appropriate conduction mechanism is proposed.