Issue 2, 2016

Tailoring the microstructure and charge transport in conjugated polymers by alkyl side-chain engineering

Abstract

Charge transport in conjugated polymers is critical to most optoelectronic devices and depends strongly on the polymer structure and conformation in the solid state. Understanding the correlations between charge carrier mobility, energy disorder and molecular assembly is therefore essential to improve device performances. Alkyl side-chains contribute to intermolecular interactions and are key to controlling the polymer microstructure and electronic properties. Investigating a set of polymers with common conjugated units but different side-chain functionalization provides new insights into the complex structure–transport relationship. Here, field-effect transistors and space-charge-limited current devices are used together with in situ grazing-incidence wide-angle X-ray scattering to study charge transport and morphology in a series of donor–acceptor copolymers. Probing hole mobility as a function of carrier density and orientation permits us to assess energy disorder and hopping rate anisotropy, while X-ray diffraction allows us to link transport properties to the polymer microstructure. We show that branched side-chains enhance structural and energy disorder and lead to isotropic transport, whereas linear chains induce either a common lamellar structure or a more exceptional pseudo-hexagonal columnar phase with a helicoidal polymer conformation. The latter enhances out-of-plane mobility but increases energy disorder possibly due to larger interring torsion angles.

Graphical abstract: Tailoring the microstructure and charge transport in conjugated polymers by alkyl side-chain engineering

Supplementary files

Article information

Article type
Paper
Submitted
19 sep 2015
Accepted
22 nov 2015
First published
24 nov 2015

J. Mater. Chem. C, 2016,4, 286-294

Tailoring the microstructure and charge transport in conjugated polymers by alkyl side-chain engineering

S. Fall, L. Biniek, Y. Odarchenko, D. V. Anokhin, G. de Tournadre, P. Lévêque, N. Leclerc, D. A. Ivanov, O. Simonetti, L. Giraudet and T. Heiser, J. Mater. Chem. C, 2016, 4, 286 DOI: 10.1039/C5TC03000E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements