Approaching disorder-free transport in high-mobility conjugated polymers

Area of Science:

• Materials Science
• Organic Electronics
• Polymer Chemistry

Background:

• Conjugated polymers are crucial for low-cost, flexible semiconductor devices.
• Despite advances, charge transport is limited by disorder in polymer films.
• This disorder hinders material design and studying electron delocalization.

Purpose of the Study:

• To investigate charge transport properties in high-mobility conjugated polymers.
• To identify molecular designs that minimize disorder and approach intrinsic transport limits.
• To understand the structural origins of improved charge transport.

Main Methods:

• Comparative transport studies using field-effect-modulated Seebeck, transistor, and optical absorption measurements.
• Analysis of a specific indacenodithiophene-based donor-acceptor copolymer.
• Molecular dynamics simulations to probe backbone conformation and disorder resilience.

Main Results:

• Several high-mobility polymers demonstrated charge transport approaching disorder-free limits.
• A specific donor-acceptor copolymer exhibited near-amorphous microstructure with excellent transport.
• Molecular dynamics revealed planar, torsion-free backbones as key to overcoming disorder.

Conclusions:

• Achieving disorder-free transport in conjugated polymers is possible.
• Planar, torsion-free backbone conformations are critical for high performance.
• These findings offer design principles for next-generation organic semiconductors.