Theory of Exciton Migration and Field-Induced Dissociation in Conjugated Polymers

TL;DR

This paper develops a theoretical framework for exciton migration, recombination, and dissociation in disordered conjugated polymers, explaining experimental photoluminescence quenching via an on-chain dissociation mechanism.

Contribution

It provides an exact expression for the photoluminescence spectrum and applies it to experimental data, highlighting the role of on-chain electron-hole separation.

Findings

Good agreement with experimental photoluminescence quenching data

On-chain dissociation mechanism explains exciton dissociation

Theoretical model matches observed field effects in conjugated polymers

Abstract

The interplay of migration, recombination, and dissociation of excitons in disordered media is studied theoretically in the low temperature regime. An exact expression for the photoluminescence spectrum is obtained. The theory is applied to describe the electric field-induced photoluminescence-quenching experiments by Kersting et al. [Phys. Rev. Lett. 73, 1440 (1994)] and Deussen et al. [Synth. Met. 73, 123 (1995)] on conjugated polymer systems. Good agreement with experiment is obtained using an on-chain dissociation mechanism, which implies a separation of the electron-hole pair along the polymer chain.