中国物理B ›› 2013, Vol. 22 ›› Issue (6): 67103-067103.doi: 10.1088/1674-1056/22/6/067103
• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇 下一篇
邸冰a, 王亚东a b, 张亚琳a, 安忠a
Di Bing (邸冰)a, Wang Ya-Dong (王亚东)a b, Zhang Ya-Lin (张亚琳)a, An Zhong (安忠)a
摘要: The inelastic scattering of oppositely charge polarons in polymer heterojunctions is believed to be fundamental importance for the light-emitting and transport properties of conjugated polymers. Based on the tight-binding SSH model, and by using a nonadiabatic molecular dynamic method, we investigate the effects of interface hopping on inelastic scattering of oppositely charged polarons in a polymer heterojunction. It is found that the scattering processes of the charge and lattice defect depend sensitively on the hopping integrals at the polymer/polymer interface when the interface potential barrier and applied electric field strength are constant. In particular, at an intermediate electric field, when the interface hopping integral of the polymer/polymer heterojunction material is increased beyond a critical value, two polarons can combine to become a lattice deformation in one of the two polymer chains, with the electron and the hole bound together, i.e., a self-trapped polaron-exciton. The yield of excitons then increases to a peak value. These results show that interface hopping is of fundamental importance and facilitates the formation of polaron-excitons.
中图分类号: (Polarons and electron-phonon interactions)