Reverse Polarization of a High-Energy Exciton in Conjugated Polymers

Polarization of a high-energy exciton in conjugated polymers is investigated theoretically by using an extended one-dimensional tight-binding Su–Schrieffer–Heeger (SSH) model. Under an external electric field, the reverse polarization of a high-energy exciton is obtained and the corresponding physical mechanism is analyzed. A critical field E_c is obtained, over which the polarization of the high-energy exciton will switch from negative to positive. In addition, by taking into account the effect of the non-degenerate confinement, we find that it is possible to realize reverse polarization through high energy photoexcitation in non-degenerate polymers.