Molecular weight dependence of exciton diffusion in poly(3-hexylthiophene)

A joint experimental and theoretical study of singlet exciton diffusion in spin-coated poly(3-hexylthiophene) (P3HT) films and its dependence on molecular weight is presented. The results show that exciton diffusion is fast along the co-facial pi-pi aggregates of polymer chromophores and about 100 times slower in the lateral direction between aggregates. Exciton hopping between aggregates is found to show a subtle dependence on interchain coupling, aggregate size, and Boltzmann statistics. Additionally, a clear correlation is observed between the effective exciton diffusion coefficient, the degree of aggregation of chromophores, and exciton delocalization along the polymer chain, which suggests that exciton diffusion length can be enhanced by tailored synthesis and processing conditions.

Citation

Haji Masri , M K Z , Ruseckas , A , Emelianova , E V , Wang , L , Bansal , A K , Matheson , A , Lemke , H T , Nielsen , M M , Nguyen , H , Coulembier , O , Dubois , P , Beljonne , D & Samuel , I D W 2013 , ' Molecular weight dependence of exciton diffusion in poly(3-hexylthiophene) ' , Advanced Energy Materials , vol. 3 , no. 11 , pp. 1445-1453 . https://doi.org/10.1002/aenm.201300210

Publication

Advanced Energy Materials

Status

Peer reviewed

DOI

https://doi.org/10.1002/aenm.201300210

ISSN

1614-6832

Type

Journal article

Rights

Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. This work is made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://dx.doi.org/10.1002/aenm.201300210

Description

Z.M. is grateful to the Government of Brunei Darussalam for financial support. The research at St Andrews leading to these results has received funding from the Engineering and Physical Sciences Research Council of the UK, and from the European Union Seventh Framework Programme under grant agreement number 321305.