Exciton Diffusion in Highly-Ordered One Dimensional Conjugated Polymers: Effects of Back-Bone Torsion, Electronic Symmetry, Phonons and Annihilation

被引：13

作者：

Pandya, Raj ^{[1
]}

Alvertis, Antonios M. ^{[1
]}

Gu, Qifei ^{[1
]}

Sung, Jooyoung ^{[1
]}

Legrand, Laurent ^{[2
]}

Kreher, David ^{[3
]}

Barisien, Thierry ^{[2
]}

Chin, Alex W. ^{[2
]}

Schnedermann, Christoph ^{[1
]}

Rao, Akshay ^{[1
]}

机构：

[1] Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England

[2] Sorbonne Univ, Inst NanoSci Paris, INSP, CNRS, F-75005 Paris, France

[3] Sorbonne Univ, Inst Parisien Chim Mol IPCM UMR 8232, Chim Polymeres, CNRS, F-75005 Paris, France

来源：

JOURNAL OF PHYSICAL CHEMISTRY LETTERS | 2021年 / 12卷 / 14期

基金：

英国工程与自然科学研究理事会;

关键词：

ISOLATED POLYDIACETYLENE CHAINS; TEMPERATURE-DEPENDENCE; SINGLET FISSION; STATE; TRANSPORT;

D O I：

10.1021/acs.jpclett.1c00193

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Many optoelectronic devices based on organic materials require rapid and long-range singlet exciton transport. Key factors controlling exciton transport include material structure, exciton-phonon coupling and electronic state symmetry. Here, we employ femtosecond transient absorption microscopy to study the influence of these parameters on exciton transport in one-dimensional conjugated polymers. We find that excitons with 2(1)A(g)(-) symmetry and a planar backbone exhibit a significantly higher diffusion coefficient (34 +/- 10 cm(2) s(-1)) compared to excitons with 1(1)B(u)(+) symmetry (7 +/- 6 cm(2) s(-1)) with a twisted backbone. We also find that exciton transport in the 2(1)Ag(-) state occurs without exciton-exciton annihilation. Both 2(1)A(g)(-) and 1(1)Bu(+) states are found to exhibit subdiffusive behavior. Ab initio GW-BSE calculations reveal that this is due to the comparable strengths of the exciton-phonon interaction and exciton coupling. Our results demonstrate the link between electronic state symmetry, backbone torsion and phonons in exciton transport in pi-conjugated polymers.

引用

页码：3669 / 3678

页数：10

共 65 条

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