# Breakdown of Polarons in Conducting Polymers at Device Field Strengths

## TL;DR

This study uses simulations to show that polarons in conducting polymers rapidly break down under typical device electric fields, questioning their role as charge carriers in such materials.

## Contribution

The paper introduces a time-dependent simulation approach to analyze polaron stability in conducting polymers at realistic electric field strengths.

## Key findings

- Polarons break down within less than a picosecond after field application.
- Breakdown occurs at electric fields as low as 1.6 mV/Å.
- Results challenge the significance of polarons as charge carriers in conducting polymers.

## Abstract

Conducting polymers have become standard engineering materials, used in manyelectronic devices. Despite this, there is a lack of understanding of the microscopicorigin of the conducting properties, especially at realistic device field strengths. Wepresent simulations of doped poly(p-phenylene) (PPP) using a Su-Schrieffer-Heeger(SSH) tight-binding model, with the electric field included in the Hamiltonian througha time-dependent vector potential via Peierls substitution of the phase factor. We findthat polarons typically break down within less than a picosecond after the field hasbeen switched on, already for electric fields as low as around 1.6 mV/{\AA}. This is a fieldstrength common in many flexible organic electronic devices. Our results challenge therelevance of the polaron as charge carrier in conducting polymers for a wide range ofapplications.