Dynamic random access memory effect and memory device derived from a functional polyimide containing electron...

Area of Science:

• Materials Science
• Polymer Chemistry
• Organic Electronics

Background:

• Functional polyimides are crucial for advanced electronic applications.
• Understanding charge transport mechanisms in polyimides is essential for developing novel memory devices.
• Existing polyimide-based memory devices often exhibit write-once-read-many-times (WORM) behavior.

Purpose of the Study:

• To synthesize a functional polyimide, hexafluoroisopropyl bis(phthalic dianhydride)/3,6-diaminocarbazole (6FDA/DAC), with electron donor-acceptor characteristics.
• To investigate the electrical bistability and memory characteristics of a device utilizing this novel polyimide.
• To elucidate the roles of donor and acceptor components in the polyimide's memory behavior through molecular simulation.

Main Methods:

• Synthesis of the 6FDA/DAC polyimide.
• Fabrication of a sandwiched memory device (ITO/Thin polyimide Layer/Au).
• Electrical characterization including conductivity state switching and ON/OFF current ratio measurement.
• Molecular simulation to understand donor-acceptor interactions.

Main Results:

• The synthesized 6FDA/DAC polyimide exhibits electrical bistability.
• The memory device shows reversible switching between low-conductivity (OFF) and high-conductivity (ON) states with an ON/OFF current ratio of approximately 10^4.
• The device demonstrates dynamic random access memory (DRAM) behavior, with the ON state being transient unless a sustained bias is applied.
• Molecular simulations provided insights into the roles of donor (DAC) and acceptor (6FDA) components.

Conclusions:

• The 6FDA/DAC polyimide is a promising material for developing dynamic random access memory (DRAM) devices.
• The observed DRAM behavior differs significantly from conventional WORM devices.
• The donor-acceptor architecture within the polyimide backbone is key to its electrical bistability and memory performance.