Leveraging solvent affinity for phase-selective doping to enhance doping efficiency in a DPP-based n-type conjugated...

Area of Science:

• Materials Science
• Polymer Chemistry
• Organic Electronics

Background:

• Phase-selective doping is key for tuning conjugated polymer electronic properties.
• Translating this doping effect to new materials remains challenging.
• Understanding solvent-polymer interactions is crucial for controlling dopant distribution.

Purpose of the Study:

• To investigate the influence of solvent affinity on phase-selective doping in conjugated polymers.
• To establish a solvent-centric strategy for optimizing polymer electronic properties.

Main Methods:

• Utilized Hansen solubility parameters to quantify solvent-polymer affinity.
• Employed coprocessing techniques with tetrabutylammonium fluoride (TBAF) dopant and a DPP-based polymer host (2PyDPP-2CNTVT).
• Conducted optical, electrical, and structural characterizations of the resulting polymer films.

Main Results:

• Solvents with high polymer affinity resulted in low solid-state order, high Seebeck coefficients (S), and low electrical conductivity (σ).
• Solvents with partial polymer and dopant affinity led to mixed phases with dopant concentration in amorphous regions.
• These mixed-phase films exhibited enhanced structural order and electrical conductivity (σ) an order of magnitude higher.

Conclusions:

• Solvent affinity is a critical factor in achieving phase-selective doping.
• A solvent-centric approach can effectively control dopant localization and optimize conjugated polymer performance.
• This strategy offers a pathway for fine-tuning electronic properties for diverse applications.