标题：Effect of intrachain configuration disorder on the exciton delocalization in π-conjugated polymers
作者：Li C.; Gao K.; Meng R.; Yang L.; Zhang M.
作者机构：[Li, C] School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China;[ Gao, K] School of Physics, State Key 更多
通讯作者地址：[Gao, K] School of Physics, State Key Laboratory of Crystal Materials, Shandong UniversityChina;
来源：Organic Electronics: physics, materials, applications
关键词：Charge transfer; Disorder effects; Exciton; Polymers
摘要：Exciton delocalization in conjugated polymers is investigated in view of its important contribution to the ultrafast charge separation recently focused in polymer solar cells (PSCs). Simulations are performed within the framework of an extended version of the one-dimensional Su-Schrieffer-Heeger (SSH) model with different molecular configuration disorders considered, including transfer integral disorder and on-site energy disorder. To quantitatively describe the exciton delocalization degree, we introduce the exciton binding energy in the numerical calculations. It is found that both the transfer integral and on-site energy disorders can effectively reduce the exciton binding energy, indicating that they should play crucial roles in facilitating the exciton delocalization. Especially, there exists a critical strength for either of the two disorder forms, beyond which only by the internal electric field in PSCs, a photogenerated exciton can be dissociated, consequently contributing to the ultrafast charge separation. In addition, we take the temperature dependent lattice vibration as an example to quantitatively discuss the realization possibility of the critical disorder strength. © 2017 Elsevier B.V.