Doping Efficiency of Poly(benzodifurandione) from First Principles

Area of Science:

• Materials Science
• Organic Electronics
• Computational Chemistry

Background:

• Poly(benzodifurandione) (PBFDO) is a promising n-type conductive polymer (n-CP) for organic electronics, especially thermoelectrics (TE).
• High-performance n-CPs are scarce, limiting TE module efficiency compared to p-type polymers.
• PBFDO offers high doping efficiency and environmental stability, making it a target for n-CP research.

Purpose of the Study:

• Investigate thermodynamic conditions favoring n-doping in PBFDO using first-principles calculations.
• Analyze the influence of temperature, polymer chain length, and doping concentration on doping thermodynamics.
• Provide insights for optimizing PBFDO doping strategies for enhanced thermoelectric performance.

Main Methods:

• Utilized first-principles electronic structure calculations.
• Computed the change in Gibbs free energy (ΔG) upon doping.
• Examined the variation of ΔG with temperature, polymer chain length, and doping concentration.

Main Results:

• Doping of PBFDO becomes thermodynamically more favorable at lower temperatures and with longer polymer chains.
• The change in Gibbs free energy (ΔG) shows a strong dependence on doping level as polymer chain length increases.
• Favorable doping levels are achievable across various chain lengths and temperatures, with identified doping thresholds for different molecular weights.

Conclusions:

• Lower synthesis temperatures can lead to more heavily doped, higher-conductivity PBFDO.
• Polymer chain length significantly impacts the achievable doping efficiency in PBFDO.
• This research offers crucial guidance for enhancing PBFDO performance in thermoelectric applications by optimizing doping strategies.