共轭聚合物中高能激子的反向极化研究

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. There exists a critical field EC, over which the polarization of the high-energy exciton will turn from negative to positive. By comparison, we obtain that the reverse polarization of a high-energy exciton is apparently larger in value than that of a biexciton or an excited polaron. Our investigation suggests that it is possible to realize reverse polarization in organic polymers through high energy photoexcitation.