Effective Model Reduction Scheme for the Electronic Structure of Highly Doped Semiconducting Polymers

Area of Science:

• Materials Science
• Condensed Matter Physics
• Polymer Chemistry

Background:

• Highly doped organic polymers are crucial for new technologies.
• Understanding the structure-charge transport relationship in these polymers is essential.
• Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) is a key example.

Purpose of the Study:

• To develop an efficient model reduction scheme for highly doped polymer chains.
• To investigate the correlation between polymer structure and charge transport characteristics.
• To elucidate the fundamental mechanisms governing charge carrier behavior.

Main Methods:

• Developed a reduced model for doped polymer chains, incorporating chemical and structural details.
• Accounted for Coulombic interactions between charge carriers (holes) and dopant ions.
• Included Coulombic repulsion between holes on the polymer chain.

Main Results:

• The model accurately reproduces the intrachain hole-density profile using a mean-field description.
• The model determines the energy distribution of doped PEDOT samples, influencing hole distribution.
• Obtained hole distribution supports the common approximation of homogeneous charge-carrier distribution.
• Spin configuration of charge carriers significantly impacts doped chain energetics, dependent on chain length, carrier density, and disorder.

Conclusions:

• The developed model provides a fundamental understanding of charge transport in highly doped organic polymers.
• This work bridges the gap between polymer structure and charge transport properties.
• The findings are critical for designing and optimizing organic electronic devices.