Switchable Charge Injection Barrier in an Organic Supramolecular Semiconductor

Area of Science:

• Materials Science
• Organic Electronics
• Supramolecular Chemistry

Background:

• Developing advanced materials with combined electronic and dipolar properties is crucial for next-generation electronic devices.
• Supramolecular self-assembly offers a pathway to create ordered structures with tailored functionalities.

Purpose of the Study:

• To disclose a novel supramolecular material integrating semiconducting and dipolar characteristics.
• To investigate the self-organization and electrical switching behavior of this material in thin films.
• To demonstrate its potential for application in nonvolatile organic memory devices.

Main Methods:

• Synthesis of a discotic semiconducting core surrounded by dipolar amide groups.
• Fabrication of metal/semiconductor/metal devices.
• Characterization of thin film self-organization via π-stacking and hydrogen bonding.
• Electrical field-induced polar order switching and analysis of charge injection modulation.

Main Results:

• The material self-organizes into hexagonal columnar structures in thin films.
• Electrical field alignment induces switchable polar order at interfaces, not in the bulk.
• Interfacial polarization modulates charge injection barriers, enabling reversible switching between high and low resistance states.
• Memory diodes exhibit switchable rectification with on/off ratios up to two orders of magnitude.

Conclusions:

• A single supramolecular material demonstrates combined semiconducting and switchable dipolar functionalities.
• The material's ability to form ordered structures and exhibit switchable interfacial polarization is key to its memory function.
• This multifunctionality presents a promising concept for developing low-cost, large-area, nonvolatile organic memory devices.