Enhanced Mobility of poly(3-hexylthiophene) transistors by spin-coating from high-boiling-point solvents

Jui Fen Chang, Baoquan Sun, Dag W. Breiby, Martin M. Nielsen, Theis I. Sölling, Mark Giles, Iain Mcculloch, Henning Sirringhaus*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

825 Scopus citations

Abstract

Chloroform is a general solvent for poly(3-hexylthiophene) (P3HT) active layers in field-effect transistors. However, its low boiling point and rapid evaporation limit the time for crystallization during the spin-coating process, and field-effect mobilities achieved for P3HT films spin-coated from chloroform are typically on the order of 0.01 cm2/(V s). Here we investigate a range of solvents with higher boiling points. We find that 1,2,4- trichlorobenzene with good solubility and a high boiling point significantly improves the field-effect mobilities up to 0.12 cm2/(V s) with on:off ratios of 106. By controlling the microstructure through the choice of solvent while keeping the molecular weight fixed, we observe a clear correlation between the field-effect mobility and the degree of microcrystalline order as measured by X-ray diffraction, as well as the strength of polaronic relaxation of charge carriers in the accumulation layer as measured by optical spectroscopy of field-induced charge.

Original languageEnglish (US)
Pages (from-to)4772-4776
Number of pages5
JournalChemistry of Materials
Volume16
Issue number23
DOIs
StatePublished - Nov 16 2004

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

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