Flexible organic bistable devices based on graphene embedded in an insulating poly(methyl methacrylate) polymer layer

Area of Science:

• Materials Science
• Electrical Engineering
• Nanotechnology

Background:

• Flexible nonvolatile organic bistable devices (OBDs) are crucial for next-generation electronics.
• Graphene's unique electrical properties offer potential for enhancing device performance.
• Poly(methyl methacrylate) (PMMA) serves as a suitable insulating layer in organic electronic devices.

Purpose of the Study:

• To investigate the electrical properties of flexible OBDs incorporating a graphene layer.
• To evaluate the charge storage capabilities and bistability of graphene-based OBDs.
• To assess the impact of mechanical stress (bending) on device performance and memory characteristics.

Main Methods:

• Fabrication of Al/PMMA/graphene/PMMA/indium-tin-oxide/poly(ethylene terephthalate) devices.
• Current-voltage (I-V) measurements at 300 K to analyze electrical properties.
• Assessment of ON/OFF ratio, endurance, and retention characteristics.
• Evaluation of device performance under static and dynamic bending conditions.

Main Results:

• Demonstrated current bistability attributed to charge storage in the graphene layer.
• Achieved a maximum ON/OFF ratio of 1 x 10^7 and high endurance of 1.5 x 10^5 cycles.
• Maintained a significant ON/OFF ratio (4.4 x 10^6) for retention times exceeding 1 x 10^5 s.
• Observed no interference effects in scaled-down devices and stable memory characteristics after repetitive bending.

Conclusions:

• Graphene integration significantly enhances the nonvolatile memory performance of flexible organic bistable devices.
• The fabricated devices exhibit excellent ON/OFF ratios, endurance, and retention, suitable for memory applications.
• The devices demonstrate robust mechanical stability, maintaining performance under bending stress, opening avenues for flexible electronics.