Tying Together Multiscale Calculations for Charge Transport in P3HT: Structural Descriptors, Morphology, and...

Area of Science:

• Materials Science
• Computational Chemistry
• Organic Electronics

Background:

• Evaluating charge carrier transport is crucial for developing advanced organic optoelectronic devices.
• Poly(3-hexylthiophene) (P3HT) is a benchmark polymer for organic semiconductors.

Purpose of the Study:

• To predict zero-field hole mobilities in P3HT using computational methods.
• To investigate the relationship between molecular nanostructure and charge transport performance.

Main Methods:

• Utilized quantum chemical calculations (QCC) and kinetic Monte Carlo (KMC) simulations.
• Analyzed approximately 100 P3HT morphologies with varying simulation volumes, structural order, and chain-length polydispersity.

Main Results:

• Hole mobility is correlated with backbone clustering and system-wide disorder from side-chain conformations.
• Strongly interconnected thiophene backbones, or "tie-chains," are essential for efficient charge transport.
• Demonstrated the ability to probe structure-performance relationships across multiple length and time scales.

Conclusions:

• Computational methods (QCC and KMC) can routinely predict charge transport in organic semiconductors.
• Molecular nanostructure, specifically backbone connectivity and disorder, significantly impacts device performance in P3HT.