Forming free resistive switching in graphene oxide thin film for thermally stable nonvolatile memory applications.

Forming free and thermally stable bipolar resistive switching behavior was observed in the memory devices composed of graphene oxide (GO) thin films on ITO coated glass substrate with Platinum (Pt) as the top electrode. The switching between the low resistance state and high resistance state showed a reliable and repeating behavior with an on/off ratio of 104 at room temperature. The Pt/GO/ITO device showed metallic and semiconducting characteristics in low and high resistance states, respectively, when resistance was measured as a function of temperature. Ohmic conduction was found to dominate in all regions of switching operation except for the high voltage regime of high resistance state where space charge limited conduction was found to be the main mechanism of current conduction. The device showed good endurance up to 104 s and retention characteristics up to 100 cycles with on/off ratio ∼104. The switching mechanism was found to be governed by migration of oxygen between GO layer and bottom ITO electrode, which was further confirmed by Raman Spectroscopy. The device exhibited stable bipolar switching characteristics with good retention and endurance properties at high temperatures up to 500 K. The graphene oxide based memory devices fabricated by simple chemical method have potential in the field of nonvolatile memory applications well above the room temperature. [ABSTRACT FROM AUTHOR]