Regioregularity effect on the self-assembly behavior of poly(3-hexylthiophene): the significance of triad sequenceElectronic supplementary information (ESI) available. See DOI: 10.1039/c6ra17250d

Poly(3-hexylthiophene) (P3HT) is one of the most widely studied conjugated polymers for applications in polymer-based photovoltaics and thin-film transistors. The regioregularity index (RR) represented by the mole percentage of the head-to-tail (HT) dyad in the polymer molecule has been considered a...

Full description

Saved in:
Bibliographic Details
Main Authors Kao, Kuei-Yu, Pei, Rou-Yuan, Chen, Hsin-Lung, Chen, Jean-Hong, Chen, Show-An
Format Journal Article
Published 22.08.2016
Online AccessGet full text

Cover

Loading…
More Information
Summary:Poly(3-hexylthiophene) (P3HT) is one of the most widely studied conjugated polymers for applications in polymer-based photovoltaics and thin-film transistors. The regioregularity index (RR) represented by the mole percentage of the head-to-tail (HT) dyad in the polymer molecule has been considered as a key factor governing both the kinetics and thermodynamics of the self-assembly of P3HT. In this study, we reveal that the configurational sequence beyond dyad plays an equally important role by demonstrating that two P3HT samples bearing almost identical RR value and average molecular weight displayed very different self-assembly kinetics. Counterintuitively, the semidilute xylene solution of the P3HT with slightly smaller RR value exhibited a much faster gelation. In the bulk state, this sample also showed faster crystallization kinetics and higher melting point. Characterization of the configurational structure by nuclear magnetic resonance (NMR) spectroscopy showed that the P3HT with the smaller RR value contained a higher population of HT-HT triad sequence. Therefore, knowledge of this system parameter, which has been omitted prevalently, is essential for the delicate control of the morphological formation of P3HT for enhancing its photophysical properties. The regioregularity index is a key factor governing the self-assembly of P3HT. We show that the configurational sequence plays an equally important role, with two P3HTs bearing an almost identical regioregularity index displaying different self-assembly behaviours.
Bibliography:10.1039/c6ra17250d
Electronic supplementary information (ESI) available. See DOI
ISSN:2046-2069
DOI:10.1039/c6ra17250d