Electric field controlled exciton transport in a conjugated polymer chain

The control of exciton transport in conjugated polymers is of fundamental importance for luminescence and photovoltaic properties of polymeric optoelectronic devices. We have investigated the elastic scattering processes of a negative polaron and a neutral exciton in a conjugated polymer chain in the presence of an external electric field. We demonstrate that the exciton can be pushed or pulled to transport in a given direction by the polaron, or migrate by exchanging positions with the polaron in particular range of electric field strength. The exciton can preserve quantum coherence in these field induced transfer processes. The manner of exciton motion depends on the spin configuration of the exciton and the polaron as well as the electric field strength. This knowledge will serve to understand the dynamics of intrachain energy transport in conjugated polymers.

► Neutral exciton can be controlled to move by electric fields by interacting with a polaron.
► Triplet excitons can be pushed or pulled by moving polarons.
► Singlet excitons can only be pulled by moving polarons.
► Both triplet and singlet excitons can perform a hopping like migration by exchanging positions with a moving polaron.