Regular Article

Exploring interchain polaron pair formation in neat conjugated polymers

¹ Department of Physics, Zhejiang Normal University, Jinhua, Zhejiang 321004, P.R. China
² Collaborative Innovation Center of Light Manipulations and Applications, Shandong Normal University, Jinan 250358, P.R. China
³ School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, P.R. China
⁴ College of Physics, Hebei Normal University, Shijiazhuang 050024, P.R. China

^a e-mail: zhensun@zjnu.edu.cn

Received: 26 November 2019
Received in final form: 6 April 2020
Published online: 15 July 2020

Abstract

We present theoretical studies to explore interchain polaron pair (PP) formation in conjugated polymers. Based on the Pariser-Parr-Pople (PPP) Hamiltonian combined with the configuration interaction singles (CIS), we perform excited-state geometry optimization on a poly-p-phenylenevinylene (PPV) dimer, and identify interchain PPs in this system by analyzing the real-space distributions of electron and hole in different excited states. We find that interchain PP states can not form in highly symmetric cofacial PPV-dimer, but can form in this PPV-dimer when applying an external electric field, rotating one of two chains, or doping an impurity. Considering that highly symmetric systems are hardly present in real polymer films, PPs should commonly exist as high-lying excited states of real polymer systems.