Partially Degradable N-Type Conjugated Random Copolymers for Intrinsically Stretchable Organic Field-Effect...

Area of Science:

• Materials Science
• Polymer Chemistry
• Organic Electronics

Background:

• Developing sustainable electronic materials is crucial for managing electronic waste.
• Conjugated polymers offer potential for flexible and printable electronic devices.
• Controlling polymer structure is key to tuning electronic and mechanical properties.

Purpose of the Study:

• To synthesize and characterize novel conjugated copolymers with tunable degradability and mechanical properties.
• To investigate the impact of combining thiophene-imine-thiophene (TIT) and thiophene-vinylene-thiophene (TVT) donor units with naphthalene diimide (NDI) acceptors.
• To explore the relationship between copolymer composition, solid-state packing, and device performance.

Main Methods:

• Copolymerization of NDI acceptor units with varying ratios of TIT and TVT donor units.
• Acid-catalyzed degradation studies to assess material sustainability.
• Structural analysis using techniques to determine molecular orientation (e.g., X-ray diffraction).
• Electrical characterization to measure charge mobility and mechanical testing to evaluate stretchability.

Main Results:

• Random copolymers (P2-P4) incorporating TIT exhibited acid-induced degradability.
• TIT promoted edge-on molecular orientation, while TVT favored face-on and end-to-end orientations.
• The optimal equimolar TIT/TVT copolymer (P3) showed enhanced electrical mobility (0.10 cm² V⁻¹ s⁻¹) and stretchability (31.3% mobility retention at 20% strain).
• P3 outperformed homopolymer P1 in mobility under strain and P5 in mobility retention.

Conclusions:

• Copolymerization of TIT and TVT allows fine-tuning of solid-state packing and molecular orientation.
• The developed materials offer a pathway to more sustainable and high-performance organic electronics.
• The synergistic effect of TIT and TVT units leads to improved stretchability and environmental degradability.