Resistance to Overdoping Allows Over 2000 S cm^-1 Conductivity in P(g₃BTTT) With Anion-Exchange Doping

Area of Science:

• Materials Science
• Polymer Chemistry
• Organic Electronics

Background:

• Chemical doping is crucial for enhancing conjugated polymer conductivity for various applications.
• Anion-exchange doping offers advantages over molecular doping, addressing limitations in bulkiness, stability, and energetics.

Purpose of the Study:

• To demonstrate anion-exchange doping in polymers with oligoether side chains.
• To investigate the factors contributing to high electrical conductivity in doped polymers.
• To understand the charge transport mechanisms and doping limits in high-performance conjugated polymers.

Main Methods:

• Anion-exchange doping of p-doped polymer films using electrolytes.
• Electrical conductivity measurements of doped polymers.
• Investigation of charge transport properties and doping effects on mobility.

Main Results:

• Achieved over 2000 S cm-1 electrical conductivity for the P(g3BTTT) polymer.
• Demonstrated that charge transport involves delocalized charges, with all generated charges participating in transport.
• Observed resilient charge mobility across nanometer to micrometer length scales.
• Identified a trade-off between charge density and mobility in the high-doping regime for most polymers.
• P(g3BTTT) showed resistance to the 'overdoping' effect, maintaining high mobility with high doubly charged species concentrations.

Conclusions:

• Oligoether side chains in P(g3BTTT) facilitate high doping levels, leading to exceptional electrical conductivity.
• The polymer's resistance to overdoping, coupled with high mobility, contributes to its superior performance.
• Anion-exchange doping is a viable strategy for developing high-conductivity conjugated polymers for advanced applications.