High performance semiconducting polymers containing bis(bithiophenyl dithienothiophene)-based repeating groups for organic thin film transistors

Kyung Hwan Kim, Dae Sung Chung, Chan Eon Park, Dong Hoon Choi

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

New dithienothiophene-containing conjugated polymers, such as poly(2,6-bis(2-thiophenyl-3-dodecylthiophene-2-yl)dithieno[3,2-b;2′, 3′-d]thiophene, 4 and poly(2,6-bis (2-thiophenyl-4-dodecylthiophene-2-yl) dithieno[3,2-b;2′,3′-d]thiophene, 8 have been successfully synthesized via Stille coupling reactions using dodecyl-substituted thiophene-based monomers, bistributyltin dithienothiophene, and bistributyltin bithiophene; these polymers have been fully characterized. The main difference between the two polymers is the substitution position of the dodecyl side chains in the repeating group. Grazing-incidence X-ray diffraction (GI-XRD) gave clear evidence of edge-on orientation of polycrystallites to the substrate. The semiconducting properties of the two polymers have been evaluated in organic thin film transistors (OTFTs). The two conjugated polymers 4 and 8 exhibit fairly high hole carrier mobilities as high as μave = 0.05 cm 2/Vs (ION/OFF = 3.42 × 104) and μave = 0.01 cm2/Vs, (ION/OFF = 1.3 × 105), respectively, after thermal annealing process. The solvent annealed films underwent reorganization of the molecules to induce higher crystallinity. Well-defined atomic force microscopy (AFM) topography supported a significant improvement in TFT device performance. The hole carrier mobilities of the solvent annealed films are comparable to those obtained for a thermally annealed sample, and were one-order higher than those obtained with a pristine sample.

Original languageEnglish
Pages (from-to)55-64
Number of pages10
JournalJournal of Polymer Science, Part A: Polymer Chemistry
Volume49
Issue number1
DOIs
Publication statusPublished - 2011 Jan 1

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Keywords

  • annealing
  • charge transport
  • conjugated polymer
  • dithienothiophene
  • mobility
  • organic thin film transistor
  • semiconductor
  • synthesis
  • thin films

ASJC Scopus subject areas

  • Materials Chemistry
  • Polymers and Plastics
  • Organic Chemistry

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