Control of polythiophene film microstructure and charge carrier dynamics through crystallization temperature

Hilary S. Marsh, Obadiah G. Reid, George Barnes, Martin Heeney, Natalie Stingelin, Garry Rumbles

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

The microstructure of neat conjugated polymers is crucial in determining the ultimate morphology and photovoltaic performance of polymer/fullerene blends, yet until recently, little work has focused on controlling the former. Here, we demonstrate that both the long-range order along the (100)-direction and the lamellar crystal thickness along the (001)-direction in neat poly(3-hexylthiophene) (P3HT) and poly[(3,3″-didecyl[2,2′:5′, 2″-terthiophene]-5,5″-diyl)] (PTTT-10) thin films can be manipulated by varying crystallization temperature. Changes in crystalline domain size impact the yield and dynamics of photogenerated charge carriers. Time-resolved microwave conductivity measurements show that neat polymer films composed of larger crystalline domains have longer photoconductance lifetimes and charge carrier yield decreases with increasing crystallite size for P3HT. Our results suggest that the classical polymer science description of temperature-dependent crystallization of polymers from solution can be used to understand thin-film formation in neat conjugated polymers, and hence, should be considered when discussing the structural evolution of organic bulk heterojunctions.

Original languageEnglish
Pages (from-to)700-707
Number of pages8
JournalJournal of Polymer Science, Part B: Polymer Physics
Volume52
Issue number10
DOIs
Publication statusPublished - May 15 2014

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Keywords

  • conjugated polymers
  • microwave conductivity
  • solid-state structure
  • structure-property relations
  • thin films

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Polymers and Plastics
  • Materials Chemistry

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