Bulk heterojunction polymer memory devices with reduced graphene oxide as electrodes

Area of Science:

• Materials Science
• Electrical Engineering
• Nanotechnology

Background:

• Polymer-based nonvolatile memory devices are crucial for flexible electronics.
• Developing efficient and stable memory devices with high performance is an ongoing challenge.
• Reduced graphene oxide (rGO) offers promising properties as an electrode material.

Purpose of the Study:

• To design and fabricate a novel polymer nonvolatile memory device structure.
• To investigate the electrical characteristics and memory effect of the fabricated device.
• To understand the carrier transport mechanisms and propose an explanation for the observed electrical transition.

Main Methods:

• Fabrication of a memory device with a unique structure: reduced graphene oxide (rGO) /P3HT:PCBM/Al.
• Characterization of the device's current-voltage (I-V) properties.
• Analysis of carrier transport mechanisms in different memory states.

Main Results:

• The device demonstrated electrical bistability with a write-once-read-many-times (WORM) memory effect.
• Achieved a high ON/OFF ratio (10^4-10^5) and a low switching threshold voltage (0.5-1.2 V).
• Identified thermionic emission current and ohmic current as dominant transport mechanisms in OFF and ON states, respectively.

Conclusions:

• The rGO/P3HT:PCBM/Al device structure is effective for polymer nonvolatile memory applications.
• The memory performance is influenced by the sheet resistance of the rGO electrode.
• Polarization of PCBM domains and localized internal electrical fields explain the device's electrical transition.