The discovery of electroluminescence in polymers has greatly promoted the development of LED. Exciton play an important role in those materials. Polyaniline

which belongs to the family of conducting polymers

has been the focus of increased physical and chemical studies in the past several years. It has been demonstrated that polyaniline may be distinguished in three discrete oxidation states

namely

leucoemeraldine-base (LB)

emeraldine-base (EB) and pernigraniline-base (PNB). The research works about exciton of the pernigraniline-base (PNB)

the fully oxidation of polyaniline

are less reported

a possible reason is that the chemical and electronic structure of this polymer are very complicated. In this paper

exciton in a PNB polymer under the electric field has been studied in the framework of the extended Ginder-Epstein model. In the earlier works

Liu Jie et al. has succeeded in explaining some experimental data of the PNB polymer by using this model and brought forth some new concepts such as combined polarons and combined solitons. Our numerical simulations showed that the exciton in this polymer is self-trapped and it consists of a bond order exciton associated with a ring torsion exciton. Further calculations showed that it will move along the main chain in weak electric field. When

E

≥3.6×10

4

V/cm

the exciton is dissociated into a pair of positive and negative polarons. Polarization of the exciton has not been found in our work. We suggest that the model be modified such as the electronic interference be considered. The results about the behavior of exciton in zero and strong electric field are very similar to those of the conducting polymers such as m-LPPP

which has ever been calculated by Li Lei et al. We still have not found the relevant experimental data

so the above numerical solutions can only be considered as a reference.